Best 3 hours

Start with the theatre across the street. Once you are inside the main area, take the dirt track to the right. It looks like a maintenance road, but it will take you to see some hidden ruins and bring you back out to the basilica. There is so much to see in there, so go early and take time to explore. There are plenty of places to take a break and rest your feet. Don't forget to look down at the mosaics that you are walking on in some places.