This imposing basilica is the largest brick church in Europe (105.5m x 66m). Covering a surface area of 4 900m2, it can accommodate up to 20 000 people. It suffered serious damage during the war, but 80% of its artistic treasures were evacuated and saved. They stand out strikingly against the immaculate white walls and columns. The church's other gem remains, in the north transept, the superb astronomical clock, standing 14m tall, built between 1464 and 1470.