Natural bridges are rock formations shaped by geological ... moon on the 755-feet (230 meters) high hill. The arch was formed when a limestone cave located inside the hills dissolved over time ...

The bats are common throughout Africa, but this cave was special—shaped like an arch with light shining in at both ends. The rock ceiling was low, which meant the bats would be close and the ...

Some caves and caverns require a permit to enter ... The centerpiece of Tonto Natural Bridge State Park is a sweeping natural travertine rock arch that creates a cavelike feel.

Recent visitors loved Arch Rock and the Alum Cave Bluffs, with several travelers noting that the trail gets steeper and more difficult on the second leg. Many also praised the well-maintained ...

Millions of shells of tiny sea creatures fell to the ocean floor after death. Compaction built up all these Calcium Carbonate shells into a 'blocky' rock called Carbiniferous Limestone.