The Astral Observatory is a location featured in Majora's Mask. It is found within the eastern section of Termina Field, just south of the entrance to Ikana. Even though the observatory is situated within Termina Field, the main way to reach this location is through a secret passage located in the Bombers' Hideout. The overseer of the observatory is an old professor named Shikashi, who searches the vast skies of Termina via the large telescope. Also, within the grounds is Pierre, a scarecrow, who can teach Link the Scarecrow's Song.
Link must access this area when trying to lift the curse set upon him by the menacing Skull Kid. Link, now in Deku form, needs to retrieve the Ocarina of Time in order to reset time back to the first day as the impending apocalypse in the form of the Moon lurks over Clock Town. Due to the fact that Deku Link can't leave Clock Town, because of his current form, he has to find another way to access the observatory. After playing a game of hide and seek with the Bombers, Link is gifted with the Bombers' Notebook as well as a specific password which enables the young hero access to their hideout.
After navigating his way through the secret passage, Link enters the interior of the observatory. Inside, Link meets Shikashi, who allows him to gaze into the giant telescope. If Link aims the telescope towards the peak of the Clock Tower, he spots the Skull Kid, who is teasing the hero from afar. Soon after, a large piece of rock comes crashing down from the Moon. This large piece of rock is in fact the Moon's Tear and it can be obtained just outside the observatory. Deku Link must trade this item with the Business Scrub in Clock Town, which enables him access to the Clock Tower.