my favorite stalactite, stalagmite reminder is that the you must hold on tight to the ceiling so you don't fall (stalagtite) and the stalagmite might reach the ceiling from the ground.
From wikepedia: A stalagmite (from the Greek stalagma , "drop" or "drip") is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. The corresponding formation on the ceiling of a cave is known as a stalactite. If these formations grow together, the result is known as a column.