Pontoosuc Turnpike……a floating bridge was used to carry the turnpike over a swamp at present day Upper Valley Road in Washington. Built in 1831, it was in use till 1839 by the turnpike, then until 1856 as a county road through Washington. The 500 foot bridge was constantly swaying or underwater to be safe for horse drawn carriages, so it was abandoned. Almost 200 years later parts of the bridge are still visible in the swamp. Courtesy of Tom Hoffman