Tower of London

The Tower of London has been whatever the Crown needed it to be for almost a millennium: William the Conqueror's statement fortress (the White Tower, 1078, still the keep at its heart), a royal palace, the Royal Mint, a menagerie, an armoury, and — the part every visitor knows — the prison where the state kept and sometimes shortened its most inconvenient people. Anne Boleyn, Thomas More, Lady Jane Grey and two young princes all ended here; Elizabeth I survived it. The graffiti carved by prisoners into the Beauchamp Tower walls is the most affecting exhibit in the place.

Do it in this order. Crown Jewels first, at opening, before the queue becomes an hour: the moving walkway carries you past the working regalia of the monarchy — the Imperial State Crown's 2,868 diamonds, the Cullinan I atop the sceptre, the coronation spoon that survived Cromwell (who melted everything else; most "ancient" pieces date from 1661 for exactly that reason). Then the White Tower's armour line of kings, then the wall walk, then Tower Green where the private executions happened, marked now by a glass memorial.

The Yeoman Warders — Beefeaters, all retired senior NCOs with decades of service, who live inside the walls with their families — run free tours every half hour that are the best value in London: history as stand-up, an hour of expertly-timed gallows humour that has been polished for five centuries. Take one early; everything you see afterwards has a story attached. And find the ravens: legend holds the kingdom falls if they leave, so the Ravenmaster keeps at least six, wings judiciously trimmed, on the payroll (they hold rank).

Book the timed entry online — the gate price is worse and summer walk-ups queue long — and give it a genuine half day. Exit along the wharf for the Tower Bridge view, and if you can, return at 9:53 PM sometime for the Ceremony of the Keys, the nightly locking ritual unbroken for 700 years (free, but tickets book months ahead).