Caverns can be under water and underground.
caverns
Carlsbad caverns
underground lunchroom.
the carlsbad caverns are the one national park which has rooms and other activities underground
no or yes
No but, a shocking discovery in 2008 led to the exploration of caverns and found lava tubes underground.
calcium carbonate
groundwater
carlsbad caverns
The town with a Spanish name famous for its underground caverns that is 80 miles west of Mason is Sonora, Texas. The Sonora Caverns, also known as the Caverns of Sonora, are a popular tourist attraction in the area.
carlsbad caverns
Underground springs.