Sapperton Canal Tunnel (South Entrance) on Former Thames and Severn Canal

The south entrance to Sapperton Canal Tunnel, part of the former Thames and Severn Canal, was built in 1789 and restored around 1980. A bronze inscription plaque in the center reads: "Coates Portal Sapperton Tunnel 1789/" (the rest is indecipherable). The engineer responsible for its design was Robert Whitworth. The structure features rock-faced and vermiculated masonry made of very large blocks, arranged in courses, with freestone dressings. The semi-circular arch rises about 1.5 meters high at the apex from the towpath and includes a keystone and voussoirs set into a band. On either side of the arch are round-headed niches topped with blind roundels, and engaged Doric columns with an entablature that extends to a string course at the top, supported by brackets below. Above each column is a domed cap, and there is a nearly square panel in the center adorned with scrolled decoration on each side and a moulded cornice shaped like a very shallow pediment. The face of the portal projects outward beyond the outer side of the columns. At the time of its construction, this tunnel was the longest in the world.