Old Elbe Tunnel or St. Pauli Elbe Tunnel, which opened in 1911, is a pedestrian and vehicle tunnel in Hamburg. The 426 m long tunnel was a technical sensation; 24 m beneath the surface, two 6 m diameter tubes connect central Hamburg with the docks and shipyards on the south side of the river Elbe. This was a big improvement for tens of thousands of workers in one of the busiest harbors in the world. Six large lifts on either side of the tunnel carry pedestrians and vehicles to the bottom.