A stalactite is an icicle-shaped formation that hangs from the ceiling of a cave.
A stalagmite is an upward-growing mound of mineral deposit. Most stalagmites have rounded or flattened tips.
When it rains calcium carbonate may drip into underground caves, if it drips it evaporates and creates stumps called stalagmites.
Stalagmites form slowly usually less than 10cm every thousand years. Radiometric dating shows that some are over 190,000 years old.
People explore the caves to see stalagmites, but if not careful they can be impaled by falling stalagmites.
150 injuries and five deaths reported in 2010 alone!
Stalagmites have no effects on land except looking nice.