Fimbulventr

Fimbulventr, also known as the Holy Mountain, is the primary setting in the second game, Bayonetta 2, and a sacred mountain related to the God of Chaos, Aesir. The city of Noatun is at its base and the mountain is worshipped like a god due to its unique connection to the Trinity of Realities including its two doors. Fimbulventr's appearance is immensely spire-like and steep, being a superlative mountain on par with many prominent mountains in the world.

Bayonetta 2
Fimbulventr was originally where Aesir observed the passing of the first eternity when the human realm was born alongside Paradiso and Inferno. Because of this, it is the only place in the world where the three realms intersect one with another, where portals to either heaven or hell are hidden away. However, the portals to the realms have never been found by human hands, as climbers and pilots trying to reach the top of Fimbulventr end up stranded or worse, most likely due to its link to both realms, making it near impossible to get to. The Cathedral Of Cascades upon the mountain's side will create a bridge however to a point where a traveler may choose to move up or down to the realm they wish.

After a demon summoning went wrong, Bayonetta travels to Fimbulventr hoping to find a way to descend to Inferno after Jeanne's soul is taken there as part of a Witch's contract with a demon. Along the way, she meets Loki who claims that he needs to reach the top of the mountain as soon as possible, though it's clear he's not entirely sure why he has to go there. Throughout their journey, Loptr oversees the events passing by beneath him and often projects/transports himself to other areas to continue his observations much like Aesir did long ago.

Trivia

 * The name Fimbulvetr, or Fimbulwinter, meaning "Harsh Winter", is the name of a terrible prophetic apocalyptic harsh winter in Norse Mythology. Along with driving snow said to come from all directions, being a winter that never ends, such a time will turn men to incessant war and murder, chaos amongst themselves, bloodshed amongst brothers, complete anarchy, and ultimately herald the end of all life in the world, before the coming of Ragnarök, the final climactic and cataclysmic bloody war of the gods that culminates into the end of the world.
 * Fimbulventr's significance in being the only point in the world of Bayonetta where all of the Trinity of Realities come together alludes to the reoccurring concept of the axis mundi, or the celestial axis, where all of the universes come together and meets at a perfect center.