Colosseum has a brutal history where they killed millions of animals, killed others for entertainment and used to feed slaves , prisoners and Christians to the lions.
There is a cafe just outside and they cheat you. They have exortionist prices and don't display the prices. A cup of coffee is like 10 Euros etc. They sting poor unsuspecting tourists. I was stung with a 100 Euro bill by these greedy swines who said it was because of the location.
The only thing I liked in Rome was a little church at the top of Spanish steps whose paintings were astonishing. This old priest wouldn't let me take a photo so I played cat and mouse with him for about 15 minutes before he gave up and I took some pics lol.