This is the abbey church of the Abbaye-aux-Hommes (Abbey for Men) founded by William the Conqueror. Begun in 1066 in the Romanesque style, it was completed in the 13C in the Gothic style. Its plain west front remains a remarkable example of Romanesque art, the austerity of which is somewhat tempered by soaring Gothic towers. Make sure you step inside to visit the east end and admire the fine 17C stalls and pulpit.