Tunbridge is the site of Australia's oldest single span wooden bridge. Spanning the Blackman River, the bridge was built by convicts in 1848 and is a rare example of a sandstone bridge with wooden decking. This bridge crosses the Blackman River at the northern end of Tunbridge. This bridge is an important symbol of the north/south boundary of Tasmania, the Blackman River being the traditional boundary between the northern and southern regions of Tasmania.
It is an impressive structure with a timber deck on top of three intermediate piers of picked stone with four spans. Each stone pier is topped with a short tower with corbelled top. Timber balustrades link the towers on either side of the bridge. It is said to be the oldest timber-decked bridge in Australia.
The bridge was used as a secret meeting place for a fascinating group of political exiles known as the 'Young Irelanders'. To avoid being seen, they arranged with the local inn to deliver their food where they gathered under the bridge. The bridge is still in use for local traffic and is a major component of the townscape of Tunbridge.