This valley south of Vielha in the Catalan Pyrenees is home to a superb cluster of 11C and 12C Romanesque churches. The buildings are renowned for their pure, plain lines, uniformity of style and for the wall frescoes that once decorated them. Reproductions of the latter can be seen in the churches - the originals are displayed in the wonderful Museu d'Art de Catalunya in Barcelona. If you have to focus on just a few churches, make sure you visit those in Erill la Vall, Durro, Boí and Taüll.