Ah! I almost forgot! Dion's Roman baths and -- most importantly -- it's public toilets! Our tour guide was VERY excited to tell us about these. Dion's public toilets were built by the Emperor Vespasian (ca. 70 AD). The radiant floor heating for the public baths was converted back into water at an open well and flushed through the adjacent public toilets. The toilets (seen in photo) seated 16, apparently. When they first opened, they were free -- but no one would use them. So the Emperor consulted a wise man who told him he should charge for them. The next thing you know people were waiting in line for hours to use the bathroom (so our tour guide story went, anyway).
It sounds like it was quite the social event!
All our photos from the trip, by the way, are available here.