The first section of tunnel passes under Newcastle Drive and the Ropewalk and is unlined, being carved from the natural Nottingham Castle Sandstone.

[4] An open section in the centre of the tunnel provides natural light and ventilation, and a staircase ascends around the wall of this opening to the junction of the Ropewalk with Upper College Street.

A second tunnel section passes under College Street whilst rising to meet Derby Road, but has been modified and partially blocked by subsequent building works, and access to Derby Road is now via a flight of stairs into the car park of the building above.

T.C.Hine was also made responsible for the later repair of Nottingham Castle and its conversion into a museum.

As built, the tunnel actually had a gradient of 1 in 12, which was considered too great for horse-drawn carriages, and as easier accesses were constructed elsewhere in The Park Estate, it never fulfilled its original purpose.