Dr. Matthew Nicholls of the University of Reading is leading a free online course on ancient Rome. The course started March 13, and runs for 5 weeks. As of today, you can still join the course and complete week 1. The course features walk-throughs of the amazing 3D Digital model of ancient Rome, circa 315 AD. While the course is free, there is the option to "upgrade" for a fee to have access to the online materials long after the course is completed, among other things.
Check out the course here:
For more information and videos, the Guardian did a nice write-up: