Mountains can be both a place and a thing. If your are going to the mountains, you are going to a place. If you say the mountain is high, you are talking about a noun, or a thing.
A cabin is a thing. A place would be where the cabin is located; at Lake Mead, in the Blue Ridge Mountains, in Morris County, in Colorado, etc.
Yes the word mountain is a noun. It is a common noun and the plural would be mountains.
A proper noun is the name of a person, place, thing, or a title; for example: Catskill Mountains, New York or The Alps, EuropeGates of the Mountains Game Preserve, MTTwin Mountains Road, Rapidan, VAArrowhead Brand 100% Natural Mountain Spring Water"Mountains Beyond Mountains", a biography by Tracy Kidder"Mountains of the Moon", 1990 movie with Patrick Bergen
A thing that can cause mountains to change is the temperature.
The Great Smokey Mountains National Park is the most visited place in Tennessee.
You can find gold in rivers, caves, and mountains but the best place to me is in the mountains.
They make it harder to get from place to place.
That depends on which country and which mountains you are thinking of.
is the ocean a place or thing
A lake is a place to visit or a thing to swim or fish in.
animals
no they are not the same thing