a mountain, a cliff
A very high hill is a mountain.
A very large hill is called a mountain.
A very high hill is typically referred to as a mountain.
A Hill.
If it is in a city, acropolis(high city).
acropolis
Tides that are not very high and not very low are called neap tides.
Walking down-hill, especially with a heavy pack, puts a very high strain on your legs.
A creep
Doing "high knees", squats, or running up a very steep hill with weights.
Driving up a very steep hill?
a creep