The British Museum holds one of the world's greatest collections of human history — eight million objects spanning two million years, though only around 80,000 are on display at any time. The building itself, with Norman Foster's Great Court glass roof enclosing the circular Reading Room, is worth the visit alone.
The Egyptian collection is the undisputed highlight for most visitors: the Rosetta Stone, which cracked the code of hieroglyphics, sits in Room 4 in a glass case that draws a perpetual crowd. The Elgin Marbles from the Parthenon fill Room 18 with spectacular fifth-century BC sculpture. Don't skip the Lewis Chessmen — 12th-century carved ivory pieces found in Scotland — or the Sutton Hoo helmet from an Anglo-Saxon ship burial.
With a whole day you might begin to scratch the surface. For a first visit, pick three or four rooms and go deep rather than racing through.
Nearest tubes: Holborn, Tottenham Court Road, Russell Square.