Ultra Crater

Ultra Crater is one of the several worlds of Ultra Space acessible though Rarity 2 and 3 White Warp Holes in Pokémon Ultra Moon after defeating Necrozma, it's the home of Celesteela.

Geography
Ultra Crater is a large volcanic wasteland with many pools of sulfur and steam geysers. The player must travel through two craters across logs to reach the end point where a newborn celesteela is growing out of the ground

Pokemon Ultra Sun and Moon
A Celesteela is found at each visit in Ultra Forest. It has an aura who boost it's Attack in two stages.