Built on top of an early Christian basilica, the collegiate church of St Ours has carved wooden stalls dating from the 15th century. In the black-and-white mosaic (12th century) in front of the altar, the scene where Samson kills the lion is surrounded by the enigmatic palindrome phrase "magic square", in an unusual arrangement (in a circle). The church is home to another treasure discovered by chance in 1945: under the roof of the former basilica, a cycle of 11th-century frescoes, the only ones of their kind in Europe.