Leaning Tower of Pisa preservation. Drilling equipment (lower left) removing soil from beneath the Leaning Tower of Pisa in Italy to correct its increasing lean. The Tower was constructed in the 12th Century as the bell tower of an adjacent cathedral (not seen). However the ground on which it was built is subject to subsidence, and the Tower began leaning from the time it was built. In 1990 it was declared unsafe, and major projects aimed at halting its lean were implemented. Lead weights were attached to the side opposite the lean to balance its weight, and cabling was attached to prevent a fall. The soil removal was started in 1998. Photographed in July 2000.