Wales

We Americans often earlier church interiors to have been bare, unadorned wood or stone. That's part of our Puritain heritage, and also partly fed by the fact that medieval cathedrals today are usually bare stone. But the medieval church would have been brightly colored - polychromed - and the walls were often decorated with elaborate paintings of religious scenes. The Painted Church website (an older site full of useful material) collects, by topic, images of most of the extant wall paintings in medieval England.