One of the world's most recognizable structures mainly because of it's angled stature, the Leaning Tower of Pisa was completed in 1372. After 200 years of construction, the ground began to sink after the first three stories were built, but construction of the tower continued. It was used as a bell tower to the cathedral nearby. As of 1984, it was 17 feet out of line and continued to keep leaning until repairs were taken in the 1990's to stop and reverse the leaning process.
		The Sistine Chapel is the famous chapel located within the Palace of the Vatican in Rome. The chapel was erected in 1473 and is a simple building in design, but it has on its walls and ceiling some of the greatest art ever produced in the western world. On the ceiling are biblical stories painted by the great artist Michelangelo in the 1500's. It took him almost 5 years to complete his work.
		The Colosseum was the largest outdoor theater of ancient Rome and still ranks among the finest examples of Roman architecture and engineering, even though it survives only as a ruin. Construction of the colosseum started around 75 A.D. The building was completed and dedicated in 80 A.D. until 404, when the colleseum was used for mock battles, combat between gladiators, battles between men and wild animals, and other public entertainment. After 404 A.D., the colosseum was largely abandoned. In the enlarged picture, you can see that the floor is no longer intact, what you see now is what was beneath the floor - the chambers that held the gladiators and animals.