Stalactite

Definition: A cave structure which look like icicles that hang from the ceiling created by water seeping through the ceiling of the cave.

“It is amazing how these stalactites have formed in the cave’s ceiling.”

Source: https://oceanexplorer.noaa.gov/facts/stalactite.html#:~:text=A%20stalactite%20is%20an%20icicle,dripping%20through%20the%20cave%20ceiling.