The Moon is Earth's natural satellite, and an important feature of Garou cosmology.
Mages view the Moon as having at least three distinct forms, depending on which side of the Gauntlet one stands on how one approaches it.
The physical surface of the moon is a barren, rocky wasteland which has been visited rarely. Darkside Moon Base occupies Daedalus crater on the outward-facing site of the moon, and has transformed a number of other craters into enormous reflector telescopes to monitor traffic in the solar system.
The Moon has a Penumbra, but the Penumbral Moon is still devoid of life--though here ruins are visible showing that this wasn't always the case. This may be the Moon that Captain Horatio Savage visited, and may in part explain why he was so adamant about not returning. Strange spirits have been known to cross the Moon's Gauntlet to harass the crew of Darkside. Victoria Station orbits in the Moon's Penumbra.
The third form of the Moon is the one known to Garou, and that is the court of Phoebe, or Sokhta, the planetary Incarna of the Moon. Sokhta is an aspect of Luna, the Celestine who is the patron of the Garou and many other Changing Breeds, and her court is home to many Lunes and other spirits sympathetic to the Garou Nation. This form of the moon is accessible from the Aethereal Reaches, like the other planetary Incarnae.
The Moon may also have some connection to Arcadia, though the nature of that connection is unclear. It is true that the lunar landing of 1969 triggered a flood of Glamour in the world that resulted in the Resurgence. Some mages have speculated that Arcadia may be the Shade Realm of the Moon, but this is purely hypothetical and the changelings have not commented on it.