The shorter of two cut and cover construction tunnels designed by Thomas Telford, under the Principal engineer of the Ellesmere Canal Company William Jessop, on the Ellesmere Canal mainline near Chirk. Construction had begun on the aqueducts to north and south in 1795 and navigation through the tunnel commenced in 1802 when the section of canal from Chirk Basin to the south to Froncysyllte in the north commenced. The tunnel is one of the first on a British Canal to have towing-paths.

The tunnel tapers out to the S portal in the form of a parabolic arch of limestone voussoirs rising to a keystone, and set slightly proud of the high rubble-faced curved retaining wall. This wall rises to a flat string course at the base of the parapet.

Stephen R. Hughes, 29.05.2007.