Begun by Christopher Wren in 1694 as a home, or hospital for ancient mariners, it became instead a school for young ones in 1873. Today the University of Greenwich has classes here. You'll notice how the structures part to reveal the Queen's House across the central lawns. Wren, with the help of his assistant, Nicholas Hawksmoor, was at pains to preserve the river vista from the house, and there are few more majestic views in London than the awe-inspiring symmetry he achieved. Behind the college are two buildings you can visit. The Painted Hall, the college's dining hall, derives its name from the baroque murals of William and Mary (reigned 1689-95; William alone 1695-1702) and assorted allegorical figures, the whole supported by trompe-l'oeil pillars that Sir James Thornhill (who decorated the inside of St. Paul's dome, too) painted between 1707 and 1717. In the opposite building stands the College Chapel, which was rebuilt after a fire in 1779 and is altogether lighter, in a more restrained, neo-Grecian style. At Christmas 1805, Admiral Nelson's body was brought from the Battle of Trafalgar to lie in state here. COST: Free, guided tours £5. Tube: DLR: Greenwich.