Undergoing refurbishment of its Great Gallery in 2014, this exquisite labyrinth of an art gallery is housed in Hertford House, an 18th-century mansion that was bequeathed to the nation, along with its contents, by the widow of Sir Richard Wallace (1818–1890). Wallace was the last in a line of wealthy aristocrats who voraciously scoured Europe in search of beautiful art. His father, the 4th Marquess of Hertford, was a particularly shrewd dealer. After the French Revolution he took a house in Paris and set about snapping up paintings by what were then dangerously unpopular artists, for a song. Frans Hals's Laughing Cavalier is probably the most famous painting here, or perhaps Jean-Honoré Fragonard's The Swing, which perfectly encapsulates the frilly rococo decadence and playful eroticism of pre-revolutionary French art. The full list of painters in the collection reads like a roll call of classical European masters, from Rubens, Rembrandt, and Van Dyck to Canaletto, Titian,
and Velázquez. English works include paintings by Gainsborough and Turner, plus a dozen by Joshua Reynolds. There are also fine collections of furniture, porcelain, Renaissance gold, and maiolica (15th and 16th century Italian tin-glazed pottery). As if the holdings aren't incentive enough to visit, the conditions of the bequest mean that no part of the collection can leave the building, so this is literally the only place in the world you'll ever see these works. Stay for lunch at the restaurant, which is elegantly sited in a glass-roofed courtyard.