The idyllic valley location of this cathedral helped protect the church from Viking raiders by hiding it from the view of invaders who came by sea. Originally founded by St. David himself around AD 600, the current building dates from the 12th century, although it has been added to at various times since. You must climb down 39 steps (known locally as the Thirty-Nine Articles) to enter the grounds; then start at the Gatehouse, with its exhibition on the history of the building. In the cathedral itself, the 15th-century choir stalls still have their original floor tiles, while the Holy Trinity Chapel contains an intricate fan-vaulted ceiling and a casket said to contain the patron saint's bones. Don't miss the Treasury and its illuminated gospels, silver chalices, and 700-year-old golden bishop's crosier. At the rear of the grounds of St. David's Cathedral are the ruins of the 13th-century Bishop's Palace, particularly beautiful at dusk. In August, guided tours costing £4.50 begin Monday at 11:30 and Friday at 2:30, and on other days by arrangement. The cathedral has a good café.