How Engineers Straightened the Leaning Tower of Pisa

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Construction on the Tower of Pisa first began in the year 1173. By 1178, the architects knew they had a problem on their hands. Built on an unsteady foundation, the tower began to sink under its own weight and soon started to lean. Medieval architects tried to address the tilt. However, it persisted and incrementally worsened over the next eight centuries. Then, in 1990, Italian authorities closed the tower to the public, fearing it might collapse. For the next 11 years, en