Former City Hall
Former offices of the Greater London Authority. A radically-designed glass fronted and rounded building, previously headquarters for London's Mayor and Assembly. City Hall has now be relocated to The Crystal, a building in Greenwich, near to the cable car. The old building is dis

Former offices of the Greater London Authority. A radically-designed glass fronted and rounded building, previously headquarters for London's Mayor and Assembly. City Hall has now be relocated to The Crystal, a building in Greenwich, near to the cable car. The old building is dis
Check the official site before travelling; hours and prices can change.
More museums

Sir John Soane's Museum
Free, tiny, deranged — Soane's own house preserved exactly as he left it in 1837.

The Wallace Collection
Free national museum in a Manchester Square townhouse — armour, Boucher, the Laughing Cavalier.

The British Museum
Free, vast, civilisationally heavy — go for one room, not all of them.
Source: wikivoyage