Guildhall, London

The Guildhall has been the ceremonial and administrative heart of the City of London for over six centuries, its great hall dating largely from the early fifteenth century. Beneath a soaring roof, banners and monuments to national heroes line walls that have witnessed state trials and civic banquets. The complex includes a hidden Roman amphitheatre discovered beneath the yard in 1988, an art gallery and one of the country's oldest municipal libraries. Figures of the giants Gog and Magog watch over proceedings.