Usually a valley or a plain.
An underwater mountain has height from the ocean bottom, the top and bottom of the mountain have depth from the surface of the water.
"Base" of a mountain is widely recognized as correct.
The 'foot' of the mountain is the very bottom of it.
The hilly land at the bottom of a mountain is called foothills. It is the transitional zone between the mountain and the flat land beyond.
The hills at the bottom of a mountain are typically referred to as foothills. They are lower elevations that gradually lead up to the base of the mountain.
platto
the bottom is widest
yes
A person on top a mountain, if that is what you mean, will get really cold because always on top of a mountain it is really chilly. While a person on the bottom of a mountain will just be warm, not high off the ground. is wrong because the mountain might not be that big so it wont be cold
The layer at the bottom of the mountain is typically the oldest, as rocks are usually deposited in chronological order with the oldest rocks at the bottom and the youngest at the top. This principle is known as the law of superposition.
valley
At the bottom; sea level