- Rome
Want proof that Rome wasn't built in a day? The Case Romane del Celio hides 20 ancient underground rooms, built on different levels under the Basilica Santi Giovanni e Paolo.
Highlights include several Roman homes from various periods, a domus (house) that was converted into an early-Christian church, and even an apartment block. These archaeological wonders date from between the second century and fourth century A.D. You see – it took much longer than a day!