Ontario is not a place most people associate with abandonment. It is Canada's economic engine, its most populated province, and the seat of wealth and political power. But beneath the thriving cities and cottage-country tourism, the province is full of places that were built with purpose and then left when that purpose ended. Mines that closed. Mills that stopped running. Towns that emptied. Railways that were pulled up. Highways that were rerouted. Ontario's abandoned places tell the story of how the province actually works: resources are extracted, communities serve the extraction, and when the economics change, the communities are left to manage the aftermath.
Categories of Abandonment
Ghost Towns
Ontario's ghost towns range from mining camps in the Near North with intact buildings to farm clearings on the Canadian Shield where only foundations and fence lines remain. The most dramatic examples are the resource towns — built fast, populated densely, and abandoned completely when the resource ran out. Burchell Lake, Cobalt's satellite communities, and Depot Harbour are examples. The quieter examples — failed farm communities along colonization roads — are harder to find but more numerous.
Industrial Ruins
Industrial ruins are concentrated along rivers and canals where water power drove the first wave of Ontario manufacturing. The textile mills of Almonte, the factories of Cornwall, and the implement works of Smiths Falls are among the most significant. Northern Ontario has a different kind of industrial ruin: mine headframes, processing plants, and the engineered landscapes of resource extraction.
Transportation Infrastructure
Ontario's abandoned railways are the most extensive category. Thousands of kilometres of rail corridor have been abandoned since the 1950s, leaving bridges, stations, rock cuts, and engineered grades across the province. Old highway alignments are another significant category — bypassed curves and abandoned road sections that show where the road used to go.
Military and Government
Cold War installations like the Foymount radar station, decommissioned military camps, and government infrastructure that outlived its purpose. The military history of Ontario is full of built-then-abandoned facilities.
Regional Guides
The best way to explore abandoned Ontario is by region, because each area has a distinct character shaped by its economic history:
- Ottawa Valley — Lumber heritage, sawmill ruins, ghost towns along colonization roads, and the OA&PS railway corridor.
- Petawawa Area — Military history, internment camps, Cold War infrastructure, and the Petawawa River log-drive era.
- Eastern Ontario — Lost Villages, textile mills, the K&P Railway, and limestone-country industrial ruins.
- Georgian Bay — Depot Harbour, island logging sites, and Booth's railway terminus.
- Near North — Cobalt silver rush, mining ghost towns, and the T&NO Railway corridor.
Before You Go
Read the ethical exploration guide, understand the legal framework around trespassing and heritage sites, and follow Leave No Trace principles. The safety guide covers the practical hazards of exploring abandoned structures. Ontario's abandoned places are fragile. What you find should be left as you found it, documented with photographs rather than removed as souvenirs.