The Catacombs of Naples Italy

The area was originally built by the ancient Greeks constructing Neapolis ( Naples )
It costs around $15.00 US so well worth it, my only issue is the groups ( divided into whatever language your guide was providing ) were too large, so you could not hear most of the information plus they were rushing you through so they could start another tour

The underground was later used by the Romans as aqueducts to supply water as seen here with the rope pulley system 

The catacombs of Naples is a subterranean network that spans for over 450kms (280 miles)

There were parts of the tunnel system where you need to go through sideways, so if your claustrophobic i would avoid

During the second World War the area was used as air-raid shelters for the military & its citizens

When the bomb raid sirens went off.....you headed underground where even childrens toys are still visible from those times

As you can see most of the area is illuminated, but (again) with these large groups the guide is far in front.

So in the narrow parts of the network  stay close as there were sections with no light & with some intersections you could go the wrong direction ( KeyTip.....have your phone flashlight engaged before entering)