Final answer:
Caves mostly form below the water table, as groundwater dissolves limestone over thousands of years to create caves with stalactites and stalagmites.
Step-by-step explanation:
Caves mostly form below the water table. When groundwater containing atmospheric CO2 dissolves limestone in a process that can take tens of thousands of years, caves are formed. Groundwater seeps into the cave and evaporates, causing precipitation of calcium carbonate and the formation of stalactites and stalagmites.