A 17th century stone fortress ruin lies in someone's backyard on the banks of the Ottawa River 90minutes east of Ottawa.

A 17th century stone fortress ruin lies in someone’s backyard on the banks of the Ottawa River 90minutes east of Ottawa. (photo: Google Maps)


When you think of a stone castle fort with gun ports and swiveling cannon bastions, images of European castle fortresses probably come to mind. A stone fortification that repels invaders with projections for pouring hot liquids and/or rocks down on attackers seems in place within medieval Europe, but yet this castle fortress lies not there, but on the Ottawa River. Hidden amidst trees in someone’s backyard, there lies the ruins of a 17th century stone fortress.

Aerial image of what remains of Fort Senneville built in 1692. (photo: Google Maps)

Aerial image of what remains of Fort Senneville built in 1692. (photo: Google Maps)

Approximately 160km east of Ottawa hidden from view on the banks of the Ottawa River sit the remains of Fort Senneville, a 17th century stone castle-fort built to protect French settlers. The fortress ruins sit in the backyard of a residence on Senneville Road, designated a National Historic Site, but out of view from the general public. The fort can however be seen with the use of aerial images such as Google Maps and Bing Maps where we can further study this fascinating piece of history under the trees.

Location of the fort in relation to Ottawa.

Location of the fort in relation to Ottawa.

Closer aerial view showing the location of the fort.

Closer aerial view showing the location of the fort.

Google streetview showing the entrance to the private residence where the fortress sits in their backyard.

Google streetview showing the entrance to the private residence where the fortress sits in their backyard.

The fort is the westernmost stone fortification built by the French on the Ottawa River when they constructed a protective string of 30 outlying forts to repel the Iroquois threat to the expansion of French settlements. Originally the fort was constructed of wood in 1671 and was attacked by the Iroquois in 1687, a year after a fortified stone mill was built on the site that also served as a watchtower overlooking the Ottawa River. The initial attack was repulsed, but the Iroquois returned in greater force in 1691 when they successfully attacked and burned the wooden fort to the ground.

A map from 1744 showing the location of Fort Senneville.

A map from 1744 showing the location of Fort Senneville.

Governor-General Frontenac then ordered the construction of a stronger, more substantial fort, and in 1692 Fort Senneville was constructed using thick stone walls and corner tower bastions, cannon ports, musket ports, and extensive swivel wall guns. Fort Senneville on the Ottawa River was the “most substantial castle-like fort” near Montreal.

My conceptual sketch of how Fort Senneville may have looked in the 1700's

My conceptual sketch of how Fort Senneville may have looked in the 1700’s

Top view sketch of the fort footprint near the Ottawa River.

Top view sketch of the fort footprint near the Ottawa River.

This new fortress was never attacked again. It remained a stronghold on the easternmost end of the Ottawa River near where it meets the St. Lawrence River, a strategic location for shipping and fur trading operations.

This imposing castle-like French fortress was ceded to the British in 1763 after the fall of New France and it remained an unused outpost. However, in 1776 during the American Revolutionary War, the fort was doomed.

Benedict Arnold, who destroyed the fort in 1776.

Benedict Arnold, who destroyed the fort in 1776.

Benedict Arnold leading his Continental Army troops in military maneuvers during the Battle Of The Cedars took over the fort and burned it to the ground as they retreated back to the United States. Arnold successfully destroyed the fort before he switched sides and joined the British around 1780.

Benedict Arnold took over then later burned the fort as he retreated to the USA during the American Revolutionary War in 1776.

Benedict Arnold took over, then later burned the fort as he retreated to the USA during the American Revolutionary War in 1776.

The ruined Fort Senneville was purchased in 1865 as a summer residence by the former prime minister of Canada and mayor of Montreal, John Abbott. The property then changed hands again in 1898 to Edward Clouston, the General Manager of the Bank Of Montreal.

A photograph of the fort exposing the ruins when the foliage has cleared during the autumn season.

A photograph of the fort exposing the ruins when the foliage has cleared during the autumn season.

A Google Map image showing what remains of the 17th century fortress.

A Google Map image showing what remains of the 17th century fortress.


Artwork from 1831 showing the ruins of the fort, which look to be in good condition at the time.


Since then the property has been privately owned and the hidden stone fortress remains cloaked under trees on the shores of the Ottawa River. It was designated in 2003 by Quebec for historical significance by classifying it as a “site historique” . Archaeological research and repairs funded by the Ministry of Culture and Communications has helped preserve what remains, and in 2009 it became a National Historic Site.


This aerial image shows the modern residences nearby with the fort in their backyard.

Bing Map image showing the ruins of the fort near the Ottawa River.

Bing Map image showing the ruins of the fort near the Ottawa River.


The ruins of the fort continue to be under private ownership and public access is not allowed. It is interesting to think that what remains of the largest stone castle-like fortress on the Ottawa River from the 17th century remains hidden in someone’s backyard, out of sight for those of us that aren’t invited to their backyard barbecue.


  1. It would be awesome even if it was a water-access only park. It has been deemed a National Historic Site, it has had public funds funnelled into research and it has received some maintenance. Whoever owns it has some pull to keep public access completely cut off.

  2. Wow !
    I am currently taking some history courses on the 7 years war/history of the British Empire; this is the sort of stuff they are discussing. It is splendid to see some of the matters like this.

  3. Vision is what this site would benefit from. There must be a way to preserve this history and for the public to share it. I was born and raised in Montreal and I did not read of this site in any history book growing up. Might take more time but I hope people, Montreal and Canada can find a way to share this piece of history. Good luck to Senville

  4. Very cool! Thanks for taking the time to research this and for sharing!

    This site should most definitely be available for access by the public.

  5. Very cool! Thanks for researching this and sharing a neat glimpse into our heritage!

    Also, this site should most definitely be available for access by the public.

  6. Can you imagine a violent group of people coming from across an ocean who invade rich vibrant ecology nurturing ‘indigenous’ (Latin ‘self-generating’)) peoples with strong heritage of peace. Invaders build forts based on the ability of their metal technology to kill & maim. Individual soldiers from a foreign regime thrive on cruelty, child-abuse, rape & pure violence. All the council-based conflict-resolution processes of First Nations are thrown aside. Today world-destroying descendants of these violent psychopaths worship them as “brave explorers & long-suffering settlers”. 30,000 years of First Nation heritage is completely suppressed & ignored. For those interesting in stepping outside of our society’s psychopathy, visit these maps of 105 First Nation (mostly Mohawk) placenames Tst-Tetsionitiotiakon Sustainability Rooted in Heritage. The greater Montreal archipelago is called Tiohtiake (Mohawk: Place where the nations & their rivers unite & divide). https://sites.google.com/site/indigenecommunity/home/5-tiohtiake-mohawk-placenames

      1. Ottawow, Thanks. If we are to learn from our colonial violence, it helps if we go deeper in our learning beyond effect to cause. European abusers had been abused by Romans, Greeks & Semites over 1000s of years. European ‘indigenous’ (Latin ‘self-generating’) Celtic peoples lived peacefully in multihome communities & cultivated massively abundant Polyculture Orchards over 1000s of years. Romans, Greeks & Semites were each in turn abused by colonial violence against them respectively. ‘Indigenous’ (Latin self-generating’) abused peoples became colonial abusers once displaced. Babylon seems to be a starting point in humanity’s millions of years of abundance & peace. Europeans came here as refugees from an ecologically & economically destroyed war-torn Europe. Only a few became Metis, fleeing the military abuse & honouring the laws & customs of these ancient peoples here. Most of remaining colonists maintained their subservient roles with colonial hierarchy & dishonoured their First Nation hosts who had fed, clothed, housed & healed them over decades. Colonists in subservience cut down 150 year old nut, fruit & greens-producing trees which produced tonnes per year with little labour in order to achieve seigneur land title. Violently denuded, the same area of ‘agriculture’ (L ‘ager’ = ‘field’) land could only produce a couple of kilograms of grains or other products per year only with huge labour. Its never too late to learn from our violence. https://sites.google.com/site/indigenecommunity/design/1-indigenous-welcome-orchard-food-production-efficiencies

    1. “and the idiot who praises with enthusiastic tone, each century but this and every country but his own, I’ve got him on the list,…and he never will be missed.”
      “Indigenous” They were. Strong heritage of peace?? Maybe the Hopi in the southwest. As for northeast woodland cultures…not so much. There is plenty of contemporary documentation that shows that Northeast woodland cultures were into human sacrifice and ritual cannibalism. They could be the best friends you ever had, or your worst nightmare. There was plenty of reason for early European settlers to refer to them as “savages.” Yet, when you compare the Iroquois Constitution with what was being written in Europe in the 12th Century, you wonder who was more civilized. An ancestor of mine had a trading post on the Mohawk River and from all accounts did not cheat the native trappers as much as the Dutch traders down in Albany. As a result, the Mohawk (or Kanienka as they called themselves) adopted him. Later they elected him as a war chief. I think this was because only war chiefs could speak before the Grand Council in Onondaga, but now they needed someone to speak before the New York Assembly in NYC. Of course this also meant that he was supposed to lead in war. He got shot in the hip at the battle of Lake George doing that. As mentioned above, they could be your best friend or worst nightmare.

      I like this article and it is too bad that some folks have to sidetrack the discussion to push some ideology or belief. Sam Champlain foolishly got mixed up in native politics in 1609, and caused the enmity for the French by my Iroquois ancestors for the next 150 years or so. The French settlers needed a stone fortress.

      The sketch shows the corner bastions as square. The photos show them as angled out a bit, in the typical way, so that eight guns could cover every inch of the fort perimeter. Just try storming the walls and get a dose of grapeshot from a six pounder in the base of the bastion. No wonder the Iroquois never attacked the stone fortress. They weren’t stupid!

  7. I am willing to bet that plenty of Canadian tax dollars have gone into this project thereby making the property more valuable when the government of Canada or provincial government of Quebec purchase it.

  8. This article brings back pleasant memories of over half a century ago. The Angus family was there at the time, my own family had also a home nearby in Senneville and I recall visiting the ruins – with permission – as a lad. Fascinatingly evocative ruins. Alexander D. Angus, who lived there was also fascinated and, in his “Old Quebec in the days before our day” evoked Fort Senneville, and it is well worth looking at. He perished in 1941 as an RCAF officer. He had left a manuscript of “Old Quebec…” and it was published by his mother after the war.

    In some ways, Fort Senneville was saved by its successive private owners who, for a long time, from Sir John Abbott on, were shareholders in the Canadian Pacific. The Senneville homes were retreats from the Montreal business world and kept private.

    The first major intrusion into the fort (after the Americans burning it down) was from a rather ill-advised Royal Ontario Museum archaeology in the 1970s. Many interesting items were found and “sneaked over the border” to Toronto. This created a considerable amount of resentment in heritage circles at the time – the Royal Ontario Museum not having advised its Quebec counterparts or anyone else, it seems. So, if anyone wishes to see and study those objects for any purpose regarding Fort Senneville, the Royal Ontario Museum weights in. Repatriation would certainly solve the uneasiness.

    Prof. Jean Belisle of Concordia University has more recently worked on the fort in a more open approach, thank goodness. This will spawn, hopefully, after “half a century of conflict” as Parkman would put it, a new and more open approach that could be taken for a possible interpretation centre dedicated to the fort and, just as important, the story of its seigneurs and also of the 1690s watch tower/windmill on the hill nearby.

    The designation of National Historic Site and that of a Quebec historic site will give some protection regarding future developers, but will not, in the foreseeable future, bring about any significant amounts of money to the site. It is a recognition under federal and provincial laws, not a reconstruction of any sort. One must recall that this is private land and even in the unlikely instance that government ownership was contemplated, one must bear in mind that Senneville is amongst the finest and most expensive real estate in eastern Canada.

    The illustrations are interesting, but, of course can only be taken as clues of Fort Senneville’s former glories. I add that there is a colour plate reconstructing it, much as your sketches, in my “French Fortresses in North America” (Osprey: Oxford) where a few pages are devoted to the Montreal west island forts since I put forward that the city’s defences rested on the network of forts outside the city as well as its wall.

    Fort Senneville may seem like an unknown, lost and isolated fort, but in its heydays, it was part of an elaborate communications and defence system.

    With kind regards

    René Chartrand
    (formerly Chief Curator, National Historic Sites, Parks Canada)

    PS – I wish you spell check would be set to UK/Canadian English rather than USA. Must we be that accommodating ?

    1. I believe that the Le Ber family, fur merchants, were the ones who put up Fort Senneville, convenient for the returning traders after their season or year up the river system

      1. Ottawow, You are technically correct, Senneville & its fort are near the end of the Ottawa river before it joins the St-Lawrence. Lac-des-deux-montagnes is an extension of the Ottawa river before it connects with Lac-St-Louis or through riviere des Prairies at Riviere-des-Prairies.

  9. Nice posting. It was fun to read through the history and see some of the pictures. It really is a pity that this isn’t available for public viewing though. I wonder if that will ever change.

  10. Everyone in our home loves your posts! We are all buffs of remnants of history gone by that evoke the imagination and that holistic feeling of time having passed. You capture these remains amazingly well with your research and artistic talents combined. Your blog is very well done and we look forward to what you are going to profile each month! Keep up the astounding work!

  11. Wow from Texas Gulf Coast! 🙂 Have enjoyed this article SO much, also of course, the pics and artworks. I want to hit every North and South American Historical site I can find. And then Europe, Great Britain and….on and on and on. In my dreams. Again, your article and the answers back and forth are tres, tres cool!

    1. Hi Kay, Glad you enjoyed the post and thanks for reading…I hope you can visit all the history you want, it is always an adventure winding back time!

  12. Excellent post. Really enjoyed your drawings. I came across Fort Senneville in the 1980s when working on a film script. In the course of research I found the Angus book, “Old Quebec in the Days before our Day” and, like you, was fascinated that the substantial remains of a 17th fort existed in someone’s back yard. So fascinated in fact that I went down there with my wife on a cold winter day and found the fort. I went back several times with friends and the then owners, Dr. Hackne and his wife, were always kind enough to let us visit the ruins. They had also paid to have the walls re-pointed by a professional mason who had worked on other historic structures. I also wrote an article on the fort that was published in the Hudson’s Bay magazine of Canadian history, The Beaver. One little item of information I have since learned about the fort is that it was the childhood playground of Canadian actor Christopher Plummer as it was the home of his close relatives.

    Given your interests, I was wondering whether you had any information about a couple of other French forts. I was in Ogdensburg a week ago and was interested in the ongoing campaign to re-built Fort de la Presentation. I know the site where the fort once stood was occupied by a series of later structures, including a rail yard. However, I have not been able to discover whether any archaeological digs were ever carried out on the site. Do you have any information in this regard?

    I was also fascinated by your post on Fort Levis. Again, do you know if any archaeological work was carried out on the site before the creation of the St Lawrence Seaway or whether remains of the three British ships sunk by the defenders were ever found by divers?

    I look forward to more of your posts.


    Mike Theilmann

  13. It’s 2 am with nothing to do in (Southern California) escaping Ottawa’s bitter cold .I came across this fascinating article on Fort Senneville. I have lived in Ottawa since 1960 having moved from Sept Iles Qc. We travelled by this so many times as children and for some reason, the name drew me to read your fine article. Love what you have done with it.

    1. Hi John, you are wise to escape the cold of Ottawa…not as bad as past years but still a lengthy bout of grey and cold to deal with. Thanks for reading and I hope to have you along on future adventures.

  14. I actually *did* know of this fort before finding this article. Having grown up a mere 7 miles away in Pierrefonds, of course, we learned all about it in school.

    Oh, wait. **No we didn’t.** To the best of my recollection, we NEVER learned about it or the other forts, save for maybe the one at Lachine. And we sure as hell never learned that it was burned down (when it was already a century old) by *Benedict Arnold* during the American Revolution.

    I did actually know about it before seeing this, though, and in fact, that’s how I found it – googling for more information. But I’ve only read about it in the last few years. I’ve even been sucked down a side rabbit-hole reading about the Iroquois though I’m trying not to get distracted. My main interest is the history of the West Island (region of Montreal) before about 1960 (IOW, before I existed and before the area was covered in housing developments). I am sort of appalled that I never knew that the three main N/S arteries were laid out in the 1700s. So nothing about pre-1701 Peace and little about settlement afterwards. Yikes.

    It so annoys me that I just started a West Island History Facebook group. Come and join. Trying to keep it to the former parishes of Sainte Anne de Bellevue, Sainte Genevieve, and Pointe Claire, but excursions are inevitable.

  15. Wow, what a great read! I am doing research on this area for a project on our towns 350 anniversary. The French Canadian fur trade brought settlers in and founded the first settlement in Michigan, here is Sault Ste. Marie.

    I believe my family traveled down the Ottawa River then on to Sault Ste. Marie, Michigan, which is a twin city name for both sides of the river, Ontario and Michigan… then on into Lake Superior.

    The challenge I have is finding the names and places they were and marking them on the map of homesteads or fur trade routes.

    Thank you for your efforts here, I’m so glad to have stumbled over this… and YES my husband and I both agree that the old fort would be an AMAZING historical site, park, etc., resurrected to live again in the imaginations of those of us who care to dream of days gone by.

    Thanks again, Michele

    1. Hi Michele, Thanks so much for the note and great interest in your area’s history. Please keep at it and if I can be of any help. please let me know…but part of the fun is the hunt for history! Good Luck!

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