Carbide Willson Ruins, Gatineau Park, Quebec, Canada.
The ruins were built in 1911 by Thomas "Carbide" Willson, who discovered a process for creating calcium carbide, which is an industrial chemical.
Willson was allegedly paranoid that competitors would steal his ideas, and tried to isolate himself in the woods to continue his experiments away from watching eyes.
After falling bankrupt and eventually dying in 1915 in New York City while trying to raise funds for another project. Willson's estate was left to ruin, where it stands today.