Lambeth Bridge

Where it sits. Lambeth Bridge crosses the Thames about half a mile upstream of Westminster Bridge, linking Millbank on the north bank with Albert Embankment on the south. The northern approach runs past Victoria Tower Gardens and the southern end of the Palace of Westminster; the southern approach lands beside Lambeth Palace, the London residence of the Archbishops of Canterbury, and the church of St Mary-at-Lambeth, now the Garden Museum. From the middle of the span you get one of the better full-length views of the Palace of Westminster, seen end-on with the Victoria Tower nearest and Big Ben's Elizabeth Tower beyond.

The story behind it. For centuries there was no bridge here at all, only a horse ferry — the only one on the Thames licensed to carry carriages, operated by the Archbishop, and remembered in the name of Horseferry Road on the north bank. A suspension bridge opened in 1862 but was so poorly built that it was closed to vehicles within thirty years and used mainly by pedestrians. The present bridge opened on 19 July 1932, designed by the engineer Sir George Humphreys with architectural treatment by Sir Reginald Blomfield and G. Topham Forrest: five steel arches on granite-faced piers, wide enough for four lanes and generous footways. It is painted red, and the colour is not arbitrary. Lambeth Bridge stands at the Lords end of the Palace of Westminster and takes the red of the House of Lords benches, while Westminster Bridge, at the Commons end, is painted green to match the Commons. Obelisks at each end are topped with carved stone pineapples, generally read as a nod to the gardener and plant collector John Tradescant, who is buried in the churchyard at St Mary-at-Lambeth a few metres away.

On screen. This is where the Knight Bus does its most famous trick. In Harry Potter and the Prisoner of Azkaban, Stan Shunpike's violently purple triple-decker hurtles through London with Harry aboard, and, faced with two red double-deckers converging in front of it, squeezes itself thin and shoots through the gap between them. The sequence was filmed on Lambeth Bridge, chosen for its straight run, its wide deck and the fact that it can be closed at night without paralysing central London. The bus itself was built as a physical three-decker prop for the standing shots, while the compression through the gap is a visual effect. On screen the geography of the chase is invented — the bus appears to career past a series of landmarks in an order no real route would follow — and it ends by depositing Harry outside the Leaky Cauldron at Borough Market, a mile downstream.

What you actually see today. A working road bridge with heavy traffic, wide pavements on both sides, and an unusually good sightline. Cross on the eastern footway for the Parliament view, and stop halfway: from here you see Victoria Tower Gardens with Rodin's Burghers of Calais and the Buxton Memorial Fountain, the Victoria Tower rising 98 metres above the Lords' end, and, on the south bank, the red-brick Tudor gatehouse of Lambeth Palace, Morton's Tower, finished in the 1490s. The bridge is also a good place to watch the tide, which runs hard here and reverses twice a day, and to see river traffic working between Westminster Pier and Vauxhall.

Getting there and timing. Westminster and Lambeth North Underground stations are each about eight to ten minutes away, Vauxhall about fifteen. The bridge is public and free at all hours. Late afternoon light strikes the Parliament facade from the west and is the best of the day for photography from the south end; after dark the floodlighting on Parliament and the lit clock faces are visible from the same spot. Traffic noise is constant, and the northern end is often affected by demonstrations and road closures around Parliament.

Making a route of it. The Garden Museum in St Mary-at-Lambeth, at the southern end, is a small and genuinely interesting museum built inside a deconsecrated church, with the Tradescant tomb in its garden. Lambeth Palace occasionally opens for guided tours. North of the bridge, the Thames Path leads past Victoria Tower Gardens to Westminster Bridge in ten minutes, or south to Vauxhall in fifteen. Tate Britain is a five-minute walk along Millbank on the north bank.