Caves Used as Road Tunnels

A rather rare thing is a natural cave used to build a road or railroad tracks through. To do this the cave has to have two entrances, be big enough and the location has to be somewhere, where a road is needed. It is easy to understand that this happens very seldom.

Caves of this type have an enormous benefit: you can visit it by driving through! On the other hand, it is rather hard to see much of the cave if you drive through with maybe 80 km/h.