London concentrates the British Museum's Rosetta Stone, the Tate Modern's converted power station, the West End's 40 active theatres, and Greenwich's Royal Observatory zero-meridian within Zone 1's tube map.
Chelsea Flower Show late May, Trooping the Colour in mid-June for the King's official birthday, and pub gardens across Hampstead and Borough finally pleasant.
Wimbledon last week of June into early July, BBC Proms run Royal Albert Hall July to mid-September, and Notting Hill Carnival the August bank holiday.
London Fashion Week mid-September, Frieze Art Fair in Regent's Park early October, and chestnuts turning in Kensington Gardens and Hampstead Heath.
Bonfire Night fireworks November 5 across Battersea and Alexandra Palace, Christmas lights along Oxford and Regent Streets, and West End matinees run year-round.