2. Towers and roof
The cathedral has two towers.
The south tower is the tallest, 136 meters high and accessible by stairs. It was built between 1368 and 1433. During wartime it served as an observation and command post.
The north tower was built between 1467 and 1511. It is 68 meters high. The North Tower is accessible by elevator for a fee. The view from the tower is spectacular,
Famous is the church's colorful roof, best seen from the north tower. It is 111 meters long and covered with 230,000 brightly colored ceramic tiles. Above the chancel on the south side of the building, the tiles form a mosaic of the double-headed eagle, the symbol of the Habsburg dynasty's rule of Vienna.