This winter there’s a chance to go deep inside Tower Bridge to see the mechanisms that make it work and the huge bascule chambers that sits below river level.

Kicking off in November, the tours take visitors on an extended look around Tower Bridge: from the 65m high Towers, high-level Walkways and vast Victorian Engine Rooms down to its hidden depths below the Thames, normally out of bounds to the public.

In addition to the usual public access, the tours include visits to the cavernous Victorian Engine Rooms, which feature the restored steam engines, accumulators and boilers used to power the bridge lifts until 1976.

Tower Bridge Senior Technical Officers then escort visitors on a tour of areas out of bounds to the public, including the Bridge Control Room and the immense brick-lined Bascule Chambers below river level.

The tours will continue from Saturday 2 November and run every Saturday and Sunday until the end of February.

They take place at this time of year as bridge lifts are fewer — which is important as the bascule chamber is needed to lift the bridge. Being inside during a lift would see you coming out very much thinner.

The tours last around 2 hours, cost £50 per person, and can be booked here.

Don’t forget that if you live in Southwark, Tower Hamlets or City of London you can visit the normal parts of Tower Bridge for just one pound – details here.