Being in the UK, I can hop down the road and see what the Roman's were up to; as you say, astounding, and over such a wide geography. Then again, 4,500 years ago in Egypt they built some majestic structures.
Agreed. The things that fascinate me the most are how simalar we were to the Romans, or Greeks for that matter. Roads, society, government, and water utilities. Even just stitting in a bar/restaurant that was a similar place back on Roman times.
Not to mention the networks of towers transmitting the latest gossip by electro magnetic radiation (ie. light) or sound. Or the tourist agencies offering voyages to festivals. Or the high speed train network ... wait a second, that doesn't sound right.