Air!
They are voids IN limestone formed by dissolution by water.
limestone
They are in Limestone.
No, not all caves are made of limestone. Caves can be formed in various types of rocks, including granite, sandstone, and volcanic lava flows. Limestone caves are common because limestone is soluble and can be eroded by water to create cave systems, but caves can also form in other types of rocks through different geological processes.
Karst caves, and it is the majority of caves; formed by acidic ground-water dissolving the limestone.
Limestone is the type of rock that is commonly found in areas with a lot of caves. Limestone is made of calcium carbonate, which is soluble in water. Over time, as rainwater seeps into the ground, it dissolves the limestone and creates openings and caves in the rock.
Limestone is the type of sedimentary rock that makes up many caves in the eastern US. These caves form when groundwater dissolves the limestone, creating underground voids and caverns.
Limestone, like the walls and roof.
limestone
Most caves are made from limestone because limestone is a sedimentary rock that is easily dissolved by water. Over time, acidic groundwater seeps into the cracks and crevices, dissolving and eroding the limestone to form cave systems. The process is known as karstification and is responsible for the creation of many limestone caves.
Limestone Caves e.g The Marble Arch Caves in Northern Ireland(Fermanagh)
They are both caves
Other way round! Water and/or air are in caves.:-) Most of the world's caves have formed / are forming in limestone.