Doge's Palace

For over a thousand years, this was the nerve centre of one of history's most successful republics — a state that lasted longer than the Roman Empire and ran a trading network that stretched from London to China. The Doge's Palace looks delicate from outside, all pink marble and white limestone lace, but inside it was pure power: courtrooms, council chambers, armouries, and prisons all under one lavishly decorated roof.

The palace was largely rebuilt after devastating fires in 1574 and 1577. The Great Council Hall, where Venice's patricians debated policy, contains Tintoretto's "Paradise" — at roughly 74 by 30 feet, it was the largest oil painting on canvas in the world when it was completed in 1592. The room itself could hold all 2,000 members of the Great Council simultaneously, making it a functioning parliament centuries before most of Europe had one.

The Secret Itineraries tour reveals what the Republic didn't want you to see: the cramped office where state inquisitors worked, the torture chamber with its ceiling so low you can't stand upright, and the pozzi — the damp ground-floor cells where prisoners went mad in the dark. Casanova was imprisoned here in 1755 for crimes including witchcraft and managed one of history's most famous prison escapes, climbing through the lead-lined roof with a metal spike he'd hidden in his Bible.

The Bridge of Sighs connects the palace to the new prison across the canal. Lord Byron gave it that romantic name in 1812, imagining prisoners sighing at their last glimpse of Venice through its small stone-barred windows. The reality was more mundane — by the time the bridge was built in 1600, most prisoners crossing it faced relatively minor sentences.