First opened in 1897, and funded by the sugar magnate Sir Henry Tate, this stately neoclassical institution may not be as ambitious as its South Bank sibling, Tate Modern, but its bright galleries lure only a fraction of the Modern's overwhelming crowds and are a great place to explore British art from 1500 to the present. The museum includes the Linbury Galleries on the lower floors, which stage temporary exhibitions, and a permanent collection on the upper floors. And what a collection it is—with classic works by John Constable, Thomas Gainsborough, David Wilkie, Francis Bacon, Duncan Grant, Barbara Hepworth, and Ben Nicholson, and an outstanding display from J.M.W. Turner in the Clore Gallery, including many later vaporous and light-infused works such as Sunrise with Sea Monsters. Sumptuous Pre-Raphaelite pieces are a major draw, while the Contemporary British Art galleries bring you face to face with Damien Hirst's Away from the Flock and other recent conceptions.
The Tate Britain also hosts the annual Turner Prize exhibition, with its accompanying furor over the state of contemporary art, from about October to January each year. There's a good little café, and the excellent Rex Whistler Restaurant has been something of an institution since it first opened in 1927. It's open daily for lunch, and for dinner on semiregular Late at Tate Friday evening events, when the gallery is open late for talks or performances; check the website for details.
Craving more art? Head down the river on the Tate Boat (£7.50 one-way) to the Tate Modern; it runs between the two museums every 40 minutes. A Family River Roamer ticket (£36 for two adults and two children) permits a day's travel, with stops including the London Eye and the Tower of London. You get a discount of roughly a third if you have a Travelcard.