The National Gallery 
The National Gallery
Displaying one of the most comprehensive collections of paintings in the world, the National Gallery is London's second-most visited museum
Description
The collections, which present an almost complete cross-section of European painting from 1260 until 1920, are especially strong in the Dutch Masters and the Italian Schools of the 15th and 16th centuries. In the Italian galleries, look for works by Fra Angelico, Giotto, Bellini, Botticelli, Correggio, Titian, Tintoretto, and Veronese, and especially for Leonardo da Vinci's Madonna and Child with St. Anne and John the Baptist, Raphael's The Crucifixion, and The Entombment by Michelangelo.
In the German and Dutch galleries are works by Dürer, van Dyck, Frans Hals, Vermeer, and Rembrandt. Among artists from the 18th century through 1920, standout works are by Hogarth, Reynolds, Sargent, Gainsborough, Constable, and Turner. French works include those by Ingres, Delacroix, Daumier, Monet (including The Water-Lily Pond), Manet, Degas, Renoir, and Cezanne.
With no-cost admission, a visit to the National Gallery is one of the top things to do in London for free. Guided tours and lunchtime lectures are also available for free and are highly recommended.
Address: Trafalgar Square, Charing Cross, London
Official site: www.nationalgallery.org.uk