Athens, Greece: Hadrian's Library

It's one thing to travel to a large area in Athens that is famous for its ancient ruins, like the Acropolis. It's another to be walking in a typical neighborhood and simply come across another such area. 

That's the case with Hadrian's Library, which probably has become a normal part of life for those living and working in the area. It was built in 132 AD. The library even had records, reading rooms and lecture spaces. The Hurulian invasion in 267 did some serious damage to the place, and it took until 412 to fix it. A century later, in the Byzantine era, churches started to pop up on the site. You can see their remains on the grounds as well.

You need to look around this place; it's a great place to visit.