London City of London Tourist Map

The City of London is not the whole of London: it is the small, ancient core, about 2.9 km² inside the line of the old Roman wall, which is why Londoners call it the Square Mile. It has its own Lord Mayor and police, and the boundary on the map is the official one; look for the silver dragons on the roads that cross it.

Londinium began here around AD 47, and you can still see it: the Roman amphitheatre under Guildhall Yard, the Temple of Mithras in the London Mithraeum and stretches of the Roman wall at Noble Street and Tower Hill. After the Great Fire of 1666 Christopher Wren rebuilt St Paul's Cathedral and dozens of churches, many of them free to step into.

Today it is a forest of towers with free views at the top: book the Sky Garden or walk straight up to One New Change and the Garden at 120. Leadenhall Market, the painted Victorian arcade, was Diagon Alley in the first Harry Potter film.

When to go: weekdays are busy and lively; at weekends the City empties, many cafés close and the streets are wonderfully quiet for walking. Stations: Bank, St Paul's, Liverpool Street, Moorgate, Cannon Street and Barbican. The Tower of London sits just outside the boundary, a five-minute walk from the Monument.