Dudley Canal Tunnel is actually a series of tunnels excavated over many years. The first section was completed in 1778 and linked limestone quarries to the Birmingham Main Line. The longest section opened in 1792 and provided a link south to the Dudley (Number 1) Canal. The tunnel was very popular - carrying up to 40,000 boats per year.
The development of railways and the opening of the almost parallel Netherton Tunnel (wider and with dual towpaths) started the slow decline in traffic and the Dudley Tunnel finally closed in 1962. A campaign to re-open the tunnel started almost immediately and this was achieved in 1973. The length of the tunnel is open to interpretation as there are some sections in the open air but it is often quoted at 3,154 yards.
Since the late 1970s, trips into the tunnel have been available through what is now the Dudley Canal and Tunnel Trust and the northern portal is within the Black Country Living Museum. Some additional sections of tunnel were bored in the 1980s which allow a circular tour of the tunnel(s) to be made.