Tower of Pisa stands at 60 metres and until 1990 was leaning at about a 10 degree angle.
Although it was designed to be perfectly vertical, it started to lean during construction.
The highly ostentatious opening ceremony, lasted one hundred days during which people saw great fights, shows and hunts involving the killing of thousands of animals (5000 according to the historian Suetonius). For the opening, the arena space was filled with water for one of the most fantastic events held in Roman times, naumachias – real sea battles reproducing great battles of the past.