This abandoned military complex offers an amazing view sitting 380 feet on top of a mountain. This site is a popular destination among people from Montreal. The abandoned complex offers dark corridors and five floors for one to explore. Historically this site has had multiple uses, see below for more details.
The following historical information was written by Sandra Stock and provided by the Laurentian Heritage Web Magazine.
"One of the most obvious landmarks in the Morin Heights and St. Adolphe d'Howard area was the large dome on top of Lac St. Denis Mountain. This enormous puffball mushroom lingered on long after the base, Canadian Forces Station Lac St. Denis, closed in 1986. There are also the remains of a village on the shore of Lac St.Denis that originally housed the base personnel.
CFS Lac St.Denis was the first installation of the Pinetree Line – a radar network createdat the height of the Cold War to detect possible enemy aircraft or missiles invading North American skies. The base was built between 1949 and 1952, officially opening on July 1, 1952. It would be one of eventually forty-four similar bases built across mainly the Laurentian Shield – hence the name “pine tree.” Farther north, there were the Mid-Canada and DEW (Distance Early Warning) lines that fulfilled similar functions. However, the Pinetree stations tended to have greater numbers of military personnel and served training functions as well.
At first, the base was viewed with apprehension by local residents as rumors of it being a nuclear weapons depot or even of the mountain being hollowed out for some mysterious purpose made the rounds. However, many civilian jobs for local people were available in its construction and on-going operation. This direct contact allayed these rumors. Also the RCAF finally improved its public relations by giving open houses, Air Force Days and tours of most of the base. Also, as there were many families stationed at Lac St. Denis, children were bused to Morin Heights School (which benefited from the military presence through government funding for expansion) and soon the Air Force became part of the wider community. In the 1950’s and 1960’s civilians participated in many activities at the base and also had access to the excellent Recreation Centre that featured an indoor swimming pool – a real luxury at that time for our area.
The personnel residences were on the shore of the lake with Private Married Quarters (PMQs) and barracks for single airmen and airwomen. Airwomen were phased out by September 1962 but had played a significant role in the first decade of the base. We see photos of them clearing bush, tracking aircraft on maps and operating radar equipment along with the men. Although there was a definite “country club” atmosphere to life at the base – with a ski hill, water sports, golf, bowling, et cetera – and plenty of parties, both on base and off – the general impression is of a serious endeavour.
By the early sixties radar equipment was automated and this, along with other developments led to the eventual reduction of base personnel. In 1986 the base was finally closed although the puffball dome lingered on for many years after.Various private sector developments were attempted at the former base but none has really proved successful. A chronic care centre was the first project but ran into financial problems and difficulties with the Municipality of St. Adolphe. An amusement park and resort was tried for a few years after that. Then the dome was dismantled and its lower part used to create a pseudo-medieval castle. This became a restaurant and semi-historic jousting performance venue. Again, this was not a success and now the property may possibly be redeveloped as a hotel."