This is from a list of 20 abandoned towns from across Canada, and up north. There are more than 3 in Ontario. It must depend on how literally, or particular, you are about what is a town versus a village, hamlet, and etc. There isn't much left of any abandoned towns, villages, or hamlets in Ontario. It could make a good road trip to see what you can find. (Be respectful of private, or any, property).

• Lemieux, Ontario

Lemieux, Ontario was founded in 1850, starting life as a mill town and farming community. According to Ontario Abandoned Places, the town was abandoned quite recently: between 1989 and 1991. The reason was that the soil on which the town was built made it vulnerable to landslides.

• Redwater, Ontario

Redwater may seem like just another ghost town but when you hear what happened here, you’ll think it should be right up there with the world’s creepiest tourist attractions. According to Ontario Abandoned Places, in 1909 the local telegraph operator was brutally beaten and died while telegraphing for help. The town was abandoned by the 1950s after the Redwater sawmill closed down.

• Altona, Ontario

According to Ontario Abandoned Places, Altona was founded in the early 1800s when Mennonites moved here from Pennsylvania. The Mennonite Church here was built in 1852. Today there are still churches, schools, a general store and some homes but most of the buildings have been boarded up and abandoned.

The following is cut and pasted from a Facebook post and comments. Sad to see the Planetarium go. I didn't know it had been vacant. I would have liked to visit once more before it was gone. I haven't been there since we went for a school trip. We moved out of Toronto, far enough that making a trip into the city was a bit of an event. Sorry Toronto McLaughlin Planetarium. How many are still left in the world?

I would have added the link to the post but Facebook links are out of control. It was 5 lines of code for one link. So, no thanks. The post came from a group, Canada is Amazing.

Toronto is saying goodbye to a piece of its space-age history. The iconic McLaughlin Planetarium, once a beloved attraction near Queen’s Park, is now being demolished after decades of sitting unused.

Opened in 1968, the planetarium welcomed over six million visitors and served as a gateway to the wonders of astronomy. It was originally gifted to the city through the Royal Ontario Museum and quickly became a hub for science education and discovery.

Over time, however, the building closed in the mid-1990s and remained vacant, slowly fading from the city’s vibrant landscape. Now, construction crews are on-site, marking the end of an era as Toronto continues to grow and evolve.

Here’s a quick look at its journey:

• Opened in 1968 as a public science and education center
• Attracted over 6 million visitors during its peak years
• Closed in the mid-1990s and remained unused for decades
• Currently being demolished as part of urban redevelopment

As the downtown core transforms, the loss of this historic landmark reflects both change and progress—while leaving behind memories of a place that once inspired curiosity about the universe.

For those unfamiliar with its history, it was donated by Colonel R.S. McLaughlin. Colonel Sam’s McLaughlin Carriage Company went onto to build cars, including the McLaughlin Buick, and later became part of General Motors. I’m sure Colonel Sam would be horrified at what has happened to his wonderful gift to the people of Ontario.

His estate, Parkwood, is still beautifully preserved in Oshawa.

• Lost Toronto 1
• Lost Toronto 2
• Lost Toronto 3

I think the sites are from Michael A. Kuch. I'm not 100% sure, it was hard to find any name at all.

Also Heritage Toronto - Another link I found while looking for old Toronto today.

I keep looking to find any image of old farms/barns from Toronto before it became a big city. There are some from what is now the area of Black Creek Pioneer Village. But, I know there must have been more. Nothing left of them, but the photos/ drawings if you can find those even.