Tower Bridge

Tower Bridge is the image most people carry of London, and the Tower Bridge experience lets you climb inside it. Completed in 1894 to cross the Thames below London Bridge without blocking the tall ships that still sailed into the Pool of London, it is a bascule bridge: its two road decks lift to let vessels pass, and they still do, many times a month. The gothic towers, designed to harmonise with the neighbouring Tower of London, conceal a steel frame, and the whole thing was a feat of Victorian engineering disguised as a castle. The paid visit has two parts. First, lifts take you up one of the towers to the high-level walkways that link them, originally built so pedestrians could cross while the bridge was raised. They now hold exhibitions about the bridge's design and history, wide views east toward Canary Wharf and west to the City, St Paul's and the Shard, and the famous glass floor panels, where you can stand above the traffic and river far below. If you time it right, watching a bridge lift through the glass is the moment people talk about. Second, a walk along the bridge brings you to the Victorian engine rooms on the south side, where the original steam engines, boilers and accumulators that powered the lifts are preserved in their green and red paint. It is a compact visit, about an hour to ninety minutes, and pairs naturally with the Tower of London next door. The bridge itself is free to walk across at any time; the ticket buys the towers, walkways and engine rooms.

The engineering story is the heart of the visit. The design, by the City architect Horace Jones and the engineer John Wolfe Barry, solved a real problem: east London was booming, crossing the river meant long detours, yet the upstream port needed open water for masted ships. The answer was a bridge that could open. The bascules were originally raised by hydraulic power, steam pumping water into huge accumulators that stored the pressure needed to lift each leaf, and the system ran until the 1970s, when it was replaced by an electro-hydraulic one. The engine rooms preserve the old machinery in beautiful condition, and the displays explain how it worked in a way that suits both engineers and curious children.

Practical sequencing: enter at the north-west tower, take the lift up, walk the east walkway and then the west, pausing on the glass floors, then descend and follow the blue line along the bridge to the engine rooms. Bridge lift times are published in advance, so if you would like to see the road open beneath your feet, check the schedule and book a slot around it. Morning visits are quieter, and the walkways have windows on both sides, so it works in any weather, which makes it a useful rainy-day option. Step-free access is available via lifts. Photographers should know the best exterior views of the bridge are from the riverside paths: the north bank by the Tower, the south bank by City Hall and Potters Fields, and Butler's Wharf to the east.

Is it worth paying for? If you have already been up the Shard or the London Eye, the views alone will not justify it. The case for Tower Bridge is the combination: the glass floor, the history of the city's most famous landmark and the engine rooms, all in an hour, and close enough to the Tower of London to make one easy morning. Combination tickets with the Tower are often available and reduce the cost. For families with children who like machines, it is one of the best-value hours in London.