Prague Castle is a walled town on a ridge above the city. Inside are three courtyards, two churches, a vineyard, a lane of small houses and a Gothic cathedral rising out of the middle of it. You go in through a gate expecting a keep and find a street. It runs 570 metres along the ridge and averages 128 metres across, which makes it the largest ancient castle complex in the world.
Prince Bořivoj put a fortified seat here around 880, and every power since has added to it rather than replaced it — Přemyslid dukes, Holy Roman emperors, Habsburg governors, and Czech presidents from 1918 on. The Old Royal Palace opens into Vladislav Hall, a room so wide that jousting was once held indoors in it. Guards change at the gates on the hour. From the eastern stairs the city drops away below the red roofs of Malá Strana, and after dark the whole ridge is floodlit.