The Tower of Pisa (Torre di Pisa in Italian), a symbol of central Italy and emblem of the Tuscan city of Pisa is the bell tower of the Cathedral, located at his bedside at the Piazza dei Miracoli (Place Miracles), whose construction began in 1173.
His fame comes from its particular characteristic inclination (which is currently at an angle of 3.99 ° south), appeared very quickly during its construction, as it was built on an alluvial plain. This defect is due to either a lack of foundation, or land subsidence due to a rock: marl.
Closed to the public for security reasons January 7, 1990 and reopened 15 December 2001, the monument was visited by 30 million people over the previous sixty years. Given the risk of collapse, significant work has been undertaken since 1993.
From a $ 28 million, they helped straighten the tower and stabilize for at least a hundred years; However, others argue that it will still be at least 300 years standing. Today it is considered stable; since the summer of 2004, she has only known physiological oscillations of small amplitude, as the scientific group responsible for the consolidation of the building. [ref. needed]
The visits were resumed from December 15, 2001, but some scientists fear it will shorten the life of the building, which is still quite fragile. Future work will help to alleviate the tower by ridding facilities clogging floors; it then becomes possible to see the sky from inside a giant telescope, as was possible before 1935.
In August 2013, after several years of stability, the Tour has started to recover with no additional work has been effectué1.
