The colosseum was used centuries ago by the emperors of rome, for entertainment, and for fun. It held the gladiators that fought in them, the gladiators fought to the death for the entertainment of the crowd and the emperor
The leaning tower of pizza is no more than a architectural mistake. the reason why it leans is because it was built on soft ground. It started to be built in 1173 and leaned over 15 ft to it's side since then! It stopped leaning in 2008 and efforts of making it last longer are still in progress.
Pompeii was originally a town made by the oscans but captured by the romans. Until Mt. Vesuvius blew its top and covered pompeii in hot ash and molten rock. it was rediscovered in 1599. Today it gets 2.5 million visitors every year.
St. Peter's Basilica Is the largest church in the world and it houses Italy's Pope. Michel Angelo himself Painted the roof of the church and was designed by Donato Bramante.