The construction of the Colosseum started around 70 to 72 AD under Vespasian, the emperor. It was later completed under Titus in the year 80 AD. Gladiatorial contests were held at the Colosseum, as well as animal hunts, mock sea battles, re-enactments of famous battles, dramas based on Classical mythology, and executions. The building was later used as an entertainment area in the early medieval era. Today the Colosseum is still standing, but in ruins from earthquakes and stone robbers.
The Leaning Tower of Pisa is a freestanding bell tower. The tower was intended to stand straight instead of slightly leaning, but because of poorly laid foundation and loose layers of rock and soil, the tower began to lean around the year 1178. The architect has not yet been identified, but many people are led to believe that Diotisalvi designed the tower.