Mount Ebott

Mount Ebott is a mountain on the Surface of the Earth. It is the only known point of entry into the Underground. It is depicted when Chara falls into the Underground and in the True Pacifist Route after the barrier is broken and everyone returns to the Surface. Eight Humans fell through the barrier on Mt. Ebott into the Underground: Frisk, Chara, and six others whose SOULs are seen in New Home.

Location
While it is never directly stated where Mount Ebott is, when Vegetoid is checked Chara says that it is "not monitored by the USDA", making the location likely to be somewhere in the United States. However, it is known that Mount Ebott is neighboring a city and at least one other mountain, as seen at the end of the True Pacifist Route when Frisk and their friends return to the surface.

Features
The most notable feature on Mount Ebott is the entrance to the Underground, located in a cave toward the top of the mountain. It also may be that Mount Ebott used to be or is still a volcano, hinted by its pointed peak, hollow nature, and changing temperatures beneath it, as well as lava. Other than that, Mount Ebott is no different than any other mountain.

Appearance
Mount Ebott is that of a normal mountain: a tall, rounded land form that rises above the land surrounding it, covered with greenery.