Although the tilt was already noted in 1640, the lean increased rapidly during the 20th century. In 1920 the overhang was 2.21 m, in 1960 it was 3.60 m, in 2001 it was 3,89 m and by 2013 it reached the present 4.60 m. The critical tipping point is considered to be 6.07 m.
In the past decade, steel inserts secured the tower from the inside but the most import measures are the steel pipes and cables linked to reinforced concrete anchors that were fitted to the bottom of the tower. These are clearly visible and are in many ways the most impressive part of the tower.
