The Leaning Tower of Pisa is one of the Seven Wonders of the World, but would probably be so anyway, even if it was vertical. The tower is the bell tower (campanile) of the cathedral with which it shares the Campo dei Miracoli. The unusual design of the tower resembles that of the Tower of Babel as described by the Creek writer Herodotus. There are 294 steps in the bell tower and seven bolls tuned to a musical scale.
Construction began in 1173, and by the time the third level was added in 1178, the lean was already noticeable. Work stopped for almost a century because of Pisa’s almost constant wars with Ihe neighbouring city state of Florence and began again in 1272 under the direction of Giovanni di Simone. Four further floors were added, at a different angle to the lower ones, but construction had to stop again in 1284 when Pisa was defeated in battle by Genoa. The bell-chamber was finally started in 1372, fully 199 years after building work had begun.
It is now known that the tilt is caused by the inadequate foundations sinking into the weak subsoil, but before this was understood various attempts lo correct the problem, such as digging out the walkway round the bottom or Mussolini’s project in which concrete was poured into the foundations, simply made matters worse.
Work started in 1999 to strengthen the foundations and remove some of the subsoil on the high side, and the tower was brought back to a lean of 13 degrees. It is now hoped that it will remain a monument to the vision of its designer and a testament to the twelfth century prestige and wealth of the city of Pisa.