Altar of the Sunne/Geography

An entrance can be seen on the other side of the Z-Crystal's pedestal from the trial in Vast Poni Canyon. It will lead the player to an immensely deep and vast canyon with an extremely long staircase with holes in some spots on the sides. At the top of it, there will be three staircases that get thinner and shorter progressively. At the top of the second, there will be paths leading in a circle on both sides. There are also two pedestals bearing the Sunne symbol on both sides of the third staircase, which leads to a center area with a rhombus-like shape with a large, Sunne symbol in the center. On the left and right of this are paths to stone "islands" with water surrounding them. These appear on each side of a crevice in the middle that is filled with water. The water surrounding the islands flows from a small stream that connects to two spires that lead to a giant circular door resting on a huge mass of rock, but it only opens in a certain part of the storyline.

Ultra Wormhole
In Pokémon Sun, after becoming, if the player has in the party at night or  during the day, they can open the dimensional distortion into an Ultra Wormhole and travel to an alternate world. This world experiences day when the other world is in night and vice versa, similar to Pokémon Moon. Unlike Pokémon Moon, however, this world's time is not offset by 12 hours from the other world's; rather, whenever the player enters this world, it is always the start of either the day or the night (6 AM or 6 PM), from which point time progresses normally so long as the player remains in the world. In this world, the Altar of the Sunne is also replaced by the Altar of the Moone, while the Lake of the Moone is replaced by the Lake of the Sunne. All other aspects (such as the Pokémon that can be found and the fashion items that can be bought) remain the same as in Pokémon Sun in this world. Traveling through the Ultra Wormhole deposits the player at the Altar of the Moone, where the distortion remains open as an Ultra Wormhole (meaning the player can return at any time without needing Solgaleo or Lunala in their party).

In Pokémon Moon, the player can access the Altar of the Sunne by creating an Ultra Wormhole at the Altar of the Moone to travel there. At the Altar of the Sunne, the distortion remains open as an Ultra Wormhole and the player can return to their own world at any time (without needing Solgaleo or Lunala in their party).

In Pokémon Ultra Sun, 's presence in the party will allow the player to travel to the Altar of the Moone in the reverse world from the dimensional distortion, provided it is in its Dusk Mane form at night or its Dawn Wings form during the day.