Did the tourist thing a little this weekend: went to Jerash.
Jerash was once Gerasa, a minor Roman city. It survived into Byzantine and early Ummayad times, then gradually dwindled away. By the 1800s there was not even a village there.
Most Roman ruins got destroyed by people coming to find cheap stone already cut. That didn't happen to Gerasa. Part of the reason is that stone is cheap around here -- it's a whole plateau of soft limestone. Another seems to be that the region around Gerasa got largely depopulated... not sure why.
But anyway, the result was that the ruins of a good-sized Roman town survived into modern times. Gerasa isn't as well preserved as Pompeii, but it's bigger -- around 100 hectares. You could walk around it all day.
(Except that you'd die from heat stroke, of course. I scrambled over rocks and peered at columns for an hour, and I got pretty toasted.)
Some random notes.
-- No walls. Well, to the east there was nothing but desert, inhabited by a few ragged nomads... and they weren't going to make any trouble while there was a Roman legion just a day's march west in Jerusalem.
-- All off-white limestone, the same stuff modern Amman is made of. Except: one column of granite, which was imported from Egypt. Why? Nobody knows.
-- Man, there were some serious lizards there.
-- The Christians didn't take over the temples of Zeus or Artemis; they turned them into living spaces or markets and built a new cathedral. Later the Arabs turned that into a mosque.
-- We're not sure how big Gerasa was, but the local Hippodrome seated 15,000. So, double that might be about right. Pretty big for a city in an arid region on the very edge of Roman rule.
-- It's not clear to me how Gerasa's economy worked. It was a net importer of food; what was it producing in return? Or was it surviving off caravan trade? I suspect the latter, because trade routes shifted after the first century of Arab rule, and that's when Gerasa began to shrivel.
I suppose I should post photographs and links and such but, really, that's not my thing. Jerash is pretty neat; if you're in Jordan, go see it.