The answer would be sea level because it is not above sea level nor is it under sea level
On the ground - the seas are on the ground.
they live underground but they are able walk around above ground.
underground has soil or is wet and above ground is dry or grassy
under ground
Underground is an adverb, as in beneath the surface of the ground. It is an adjective, as in an underground car park
Copper is mined in pits ... which were underground at one point in time and are now above ground albeit at a lower elevation.
ground under you
Underground.
It grows above ground.
Where are ground locations on engine 1982 camaro z28
A pumpkin grows above the ground. A pumpkin grows above the ground.
No, its called the underground railroad because they were "hidden".