The Observatory is the home and headquarters of the Celestrians where they watch over the World Tree, Yggdrasil, and mortalkind. The only way to reach it is by a portal or by the Starflight Express, which is piloted by Stella and Sterling.
The location appears as a playable board in Fortune Street. The board is shaped like the head of a spade, with one of the districts being in a section of the board that moves when a player lands on a switch. The Starflight Express train goes around the screen when this happens. There is also a portal leading to and from this area. In Tour Mode, the player has to come in at least 3rd against Stella, Slime and Kiryl to beat the board.