The oldest building in the city is the Duff-Baby House built in 1798. Considered the oldest house in the entire southwestern part of Ontario, this home was built by Alexander Duff to be a fur trading post. The home was acquired by Jacques Baby in 1807, and was used as the headquarters of U.S. General Harrison until it was ravaged during the War of 1812.

The 2 1/2 storey timber structure was refinished as Baby's residence in 1816. Located at 221 Mill Street in Old Sandwich Town, you’ll see one of the best-preserved and oldest Georgian-style houses in Ontario. Today the house is owned by the Ontario Heritage Foundation.