1.   The large limestone caves are also quarried for cement.

2.   Another possible hiding spot is the network of limestone caves in the vicinity.

3.   After World War II, his curiosity turned to astrophysics when he investigated radiation deep inside limestone caves in the Blue Ridge Mountains of Virginia.

4.   Buses ferry tourists on excursions to a nearby limestone cave or on scuba diving expeditions.

5.   He thinks that something about the limestone cave may have favored the durability of the Caucasus Neanderthal DNA.

6.   It is a limestone cave on the island of Salamis with a view of the bay, a roomy fixer-upper with great footpath appeal.

7.   That environment is Devils Hole, a limestone cave filled year-round with warm water that flows up from an underground aquifer.

8.   The limestone cave resembles the shape of the outer ear and has high-fidelity acoustical qualities.

9.   The system of limestone caves was not the only challenge for the pursuers.

10.   This is actually three connected limestone caves.