Stalactite – water dripping from the roofs of caves leave behind microscopic particles of calcium carbonate. These build up as icicle shaped stalactites.

The video below shows stalactites at Peak Cavern, Castleton in the Peak District.

Stalagmite – drips splashing onto the floor of caves leave behind microscopic particles of calcium carbonate. These build up on the floor of caves.

Pillar – when a stalagmite and stalactite join a pillar is formed.

Cavern – an underground cave that has been hollowed out by the action of underground streams and by carbonation and solution.

The video below shows a range of limestone landforms found underground.