St Vitus Cathedral fills the middle of Prague Castle, and the surprise inside is the colour. Its glass is twentieth-century rather than medieval, and on a bright afternoon it throws the whole spectrum across the stone. The strangest room is the chapel of St Wenceslas, whose lower walls are set with over a thousand slabs of polished jasper and amethyst. In the triforium above, a row of carved heads looks down — the men who built and paid for the church, cut as portraits.
The building took 585 years. Charles IV began it in 1344 with Matthias of Arras from Avignon; when he died, a young German mason named Peter Parler took over and gave the choir its net vaults. Then the Hussite wars stopped the work, and it stayed stopped for four centuries. The western front, the nave and the rose window are barely a hundred years old, and the consecration came in 1929. From the floor the join is invisible — the shafts run up unbroken and the eye goes with them.