The Postal Museum has announced fresh dates for the chance to walk through the tunnels under Mount Pleasent where the Mail Rail used to carry the post.

Visitors get access to the original tunnels, tracks and station platforms of London’s 100-year-old postal railway, letting you explore parts of the railway that aren’t accessible on the Mail Rail ride.

The route involves walking on uneven ground in low-light conditions for around 1.2km (0.75 miles) including stepping across rails and up onto platform areas. For this reason, the walk is not accessible by wheelchair users and is not recommended for people with mobility impairments.

Tunnel Walks will take place at 3pm, 3:30pm, 6pm and 6:30pm on the following Tuesdays:

• 4th and 25th October (25 October only departing at 6pm and 6:30pm)
• 1st, 15th and 22nd November
• 6th and 13th December (Christmas Tunnel Tours)

The Christmas Tunnel Walks in December follow the same route as a standard walk, but access a small section of the tunnels not usually on the walking route, to reveal a surprising festive scene.

The tunnel walks cost £55 and can be booked from here.