London's attraction as a destination rests partly on sheer quantity — there is more to see and do here than in most entire countries — and partly on the fact that a large proportion of its greatest institutions are free. The British Museum, the National Gallery, the Natural History Museum, the Victoria and Albert Museum, the Tate Modern, and the Science Museum all charge nothing for their permanent collections. This is unusual by world standards and means that a week in London can be culturally rich regardless of budget.
The obvious sights — Tower of London, Tower Bridge, the London Eye, Buckingham Palace, the Houses of Parliament and Trafalgar Square — are obvious for reasons: they are genuinely impressive. But the city rewards going slightly off the main tourist routes. Hampstead Heath gives you open countryside within the city. Greenwich combines maritime history, Royal Observatory, and one of the best city views. Sir John Soane's Museum and Leighton House are two of the strangest and most beautiful domestic interiors in Europe.
For history with a hook, the Churchill War Rooms preserve the underground bunker Churchill ran the Second World War from. Shakespeare's Globe on the south bank is an open-air reconstruction of the 1599 theatre. The Victorian arcade of Leadenhall Market and the haunted Magnificent Seven cemetery at Highgate give you the city's more atmospheric corners.
For a free panoramic view of the City, book a slot at Sky Garden on top of the Walkie-Talkie. For parks, Hyde Park is the centrepiece but the Royal Parks network extends east to St James's Park and Green Park, both ideal for walking between sights in the Westminster area.
Walking is underrated as a way to see London. The South Bank walk from Westminster Bridge to Tower Bridge is one of the great urban strolls. The canal towpath through Regent's Park to Camden is another. The City of London on a Sunday morning, when the streets are empty and the churches are open, is a different city from the weekday financial district.