The Lake Light
This lighthouse, one of the earliest on the Great Lakes, was completed in 1808 as an hexagonal tower 16 m high, topped by a wooden cage with a fixed whale-oil lantern. In 1832 it was raised to 25 m and later equipped with a revolving light. The mysterious disappearance of its first keeper, J.P. Rademuller, in 1815 and the subsequent discovery nearby of part of a human skeleton enhanced its reputation as a haunted building.
Plaque via Alan L. Brown's site Toronto Plaques. Full page here.