The huge walls towering over the roofs of the Old Town tenement houses belong to the oldest temple in Toruń - the cathedral of St. Johns. Its construction began in the 13th century and continued in stages for over 200 years. In this very cathedral, in 1473, the famous Nicolaus Copernicus was baptized, and this is also a place where rests the heart of King Jan Olbracht, who died in 1501 in Toruń. The cathedral tower houses the largest medieval bell in Poland - Tuba Dei ("God's Trumpet"). Its sound welcomed kings arriving in Toruń and also accompanied the most important events in the history of the city. Today it is only heard during exceptional circumstances. You can see it by climbing the cathedral tower, from where you can see an amazing view of Toruń's Old Town. On the southern wall of the tower, an unusual clock attracts attention. This is the Rafters' Clock, which measures time with only one hand, ending with a hand and a finger. Hence it is called Digitus Dei - the Finger of God. Its richly decorated shield face the Vistula River and once served rafters sailing there.