The Garisenda tower is currently at a slant of four degrees, in comparison to Italy’s other famous Leaning Tower, in Pisa, which is angled at five degrees
A historic landmark in Bologna, Italy is currently closed to the public as the city fears it could collapse.
Known as one of the city’s Two Towers, the Garisenda tower is in danger of collapsing due to the deterioration of materials at the base of its structure, the Comune di Bologna’s official website states. The 158-foot tower stands beside the Asinelli tower, which is nearly twice as tall at 318 feet and offers sweeping views of the city from the top.
Both towers are closed to the public as the Garisenda tower is being restored in an effort to prevent a possible collapse while the Asinelli tower is closed for maintenance.
According to CNN, an investigation in October confirmed that the stone used for the base was disintegrating and the bricks above had cracks in them that were expanding.
The outlet previously reported that the site has been monitored since 2018 and in October, the city installed acoustic sensors to record any noises from cracks and creaks. A pendulum to monitor movement was also installed in both the Garisenda and Asinelli towers.
In comparison to Italy’s other famous Leaning Tower, in Pisa, which is angled at five degrees, the Garisenda tower is currently at a slant of four degrees.
On Friday, city officials announced that the project to restore the Garisenda tower would cost about $4.7 million and maintenance will continue through February, according to the Associated Press.
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human-interest stories.
Both towers were constructed between 1109 and 1119, and they were named after families who lived in the city at the time. During the middle ages, families wanted to build the tallest towers in the city in order to show off their social status and wealth, the official website of the Bologna-Modena Tourist Territory states.
The Asinelli tower features 498 steps total that lead up to the top. Meanwhile, the Garisenda tower was once taller but it had to be lowered in the 14th century out of fear that it would collapse. Its steepness was so severe that Dante Alighieri wrote about it in his famous poem “Inferno,” which was completed in the early 1300s.
For more People news, make sure to sign up for our newsletter!
Read the original article on People.