Guildhall Art Gallery

Lonely Planet review

The gallery of the City of London provides a fascinating look at the politics of the square mile over the past few centuries, with a great collection of paintings of London in the 18th and 19th centuries. The real highlight of the museum is deep in the darkened basement, where the archaeological remains of Roman London's amphitheatre, or coliseum, lie.

Discovered only in 1988 when work finally began on a new gallery following the original's destruction in the Blitz, the remains were immediately declared an Ancient Monument, and the new gallery built around them. While only a few remnants of the stone walls lining the eastern entrance still stand, they're imaginatively fleshed out with a black-and-fluorescent-green computer-generated trompe l'oeil. Markings on the square outside the Guildhall mark out the original extent of the amphitheatre.

A sculpture of former prime minister Margaret Thatcher, which has to be housed in a protective glass case as the iron lady was decapitated here by an angry punter with a cricket bat soon after its installation in 2002. Today, following some tricky neck surgery, the Maggie has finally rejoined the gallery's collection, but her contentious legacy lives on.