Lyndhurst bridge is reportedly the oldest surviving bridge in Ontario, Canada, having been completed in 1857.^[1][2] It is located in the community of Lyndhurst, in the township of Leeds and the Thousand Islands. The bridge is a three span stone arch bridge.^[2] The bridge, constructed of local sandstone, was designed by John Donald Roddick, a local mill owner, and was built by Miles Fulford and Simon Ransom.^[3] In 1986 the bridge was altered by the addition of an interior frame of load-bearing reinforced concrete inside the deck system.^[2] It carries Lyndhurst Road in a single lane across the Gananoque River.