from vertical Now the tower is known more for its tilt than for anything else The Leaning Tower of Pisa is called Torre Pendente di Pisa in Italy It is in northwestern Tuscany in the country's central region The tower is found in the walled Piazza dei Miracoli This area's name means square of miracles The tower is one of several buildings that make up the church grounds there The others include the baptistery and the cathedral The Piazza dei Miracoli is also called the Piazza del Duomo In Italian the word duomo means cathedral Construction started on the tower on August 9 1173 No one wanted the tower to tilt or lean A leaning tower could possibly fall over It would have been an embarrassment But the tower was built near the sea It was on soft silty soil Because the tower is made of marble it is very heavy and sank into this soil The cathedral is surrounded by a large grassy space
THE TOWER TELLS A STORY The Leaning Tower of Pisa has been through a lot It took almost 200 years to complete It was not finished until 1372 Some of the long breaks in construction were because of wars For centuries after it was done its tilt slowly worsened In recent decades engineers THINK ABOUT THE SOIL The type of soil upon which a building stands is important Some kinds of soil are softer than others Some soils have a lot of clay and sand in them This silty soil contains small particles Other soils have a lot of gravel in them Gravelly soil contains large particles The best soils are those that do not change shape under a building's weight This will keep the structure from shifting or leaning Today builders know a lot more about soil than they did in the past They can make the ground safe before building have worked to save the tower from the disaster of collapsing The tower is now a tourist attraction Every year more than 6 million people visit the city of Pisa They want to see the Piazza
dei Miracoli and its tilted tower Pisa relies on the money tourists spend there when they visit In the 1990s the tower had to close to the public for many years Engineers were worried that it could fall over If that happened people could get hurt or killed A collapse would also harm the area's tourism industry The work to keep the tower from falling PERSPECTIVES over was not easy A LONG TERM It took many years PROJECT of engineering and Naturally a tower that took nearly 200 years to complete modern technology had many builders Historians In 2001 the tower are not exactly sure who deserves credit for building reopened The tilt the tower Many experts credit was lessened and the the first stage of building to Bonanno Pisano Later stages tower was stabilized were worked on by Giovanni However engineers Pisano Tommaso Pisano and other architects did not correct the tilt entirely The Leaning Tower of Pisa continues
