One of the highlights from my Italy trip was when I spent the day at the Colosseum and the Roman Forum. In the morning before heading to my next airbnb I went to Piazza Navona since it was only a 5 minute walk. I've always been fascinated with Rome's history (I'm a history major) and couldn't believe my eyes once I stepped into the historic site. To be honest, the Roman Forum was worth spending time over the Colosseum. I was inside the Colosseum for about 30 minutes or so and many parts were blocked off due to construction. I spent almost 3 hours at the Roman Forum, its huge! So much to see and explore once you're inside. My tip would be to first go to the Roman Forum first instead of waiting in line for the Colosseum, because it can take awhile. Take your time and don't rush, but if you do have extra time I would suggest walking over to Altare della Patria. It's stunning! You can go up to the top and see the sunset from there - it's beautiful.