The Observatory (天使界, lit. "Angel World" in Japanese) is the heavenly home of the Celestrians in Dragon Quest IX. It is located high about the Protectorate and is accessible only by a portal, or the Starflight Express. The Yggdrasil Tree is located at the pinnacle of the Observatory.
After the events in Coffinwell, the hero is taken back to the Observatory with the help of his new companion; Stella. During events prior to this point in the game, the hero witnesses a frightening nightmare. In it, a dark cloud is seen, and the hero hears a strange voice that informs them that of one their own will try to destroy mortalkind. However it also tells that one will save them. The hero visits Apus Major and informs him of the nightmare. Apus Major then says that the player must collect the fallen Fyggs and bring them back. The hero, accompanied with Stella, then descends back into the Protectorate.
During the next visit to the Observatory, the hero rushes to Apus Major and informs him of a betrayal and theft. The wise Celestrian proves him wrong and tasks the hero with the deliverance of the Fyggs. Once this is completed, the hero is attacked as he descends back to the Protectorate. This can be considered the "last" visit to the Observatory.
Dragon Quest XI 3DS and Switch
The Observatory is the first location available through the altar of the starry skies in the Echo Chamber. Only the zenith of the building is available to explore, with Aquilla, Pavo, and a slime present. The former two are astonished that a party of mortals made it to the realm, and doubly so that they can see the angels on top of that.
Aquila is concerned over a fygg going missing, and only has a scant clue to work with in finding it. The player is prompted with helping the celestrian, and he mentions that when he searches his mind, the words "Ruby Path of Doom" are all that appear. With this clue, the Luminary and his companions head out to the grotto and find that a Liege lizard is the culprit behind the fygg's disappearance. After defeating the dragon, it is revealed to be nothing more than a slime that wished with all its heart to become as strong as it could. Sparing the glob of goo, the Luminary returns with the fygg to Aquilla's amazement.
The Observatory appears as a board in Fortune Street, where the switches will move a district around the main board section as if it were the starflight express.