Moonbase One
Moonbase One is a base on one of Cybertron's moons, with the other one naturally being the location of Moonbase Two.
Fiction
The Transformers cartoon

In 2005, it was primarily an Autobot command base during fight against Decepticon-controlled Cybertron. Many Autobots were stationed on Moonbase One, including Optimus Prime, Ratchet, Ironhide, Prowl, Brawn, and the Dinobots, but only Jazz and Cliffjumper were left behind when Optimus Prime went to provide reinforcements to Autobot City.
Not too long afterwards, Moonbase One was targeted and devoured by Unicron. It spent a while being slowly digested within Unicron's bowels, up until he was obliterated by a mystical glowing thingy. The Transformers: The Movie
Animated
Moon Base One is Cybertron's inner moon, and serves as a major industrial center with plenty of energon farms and processing facilities. The AllSpark Almanac II
Exodus
Moon Base One was built during the Golden Age of Cybertron. It was occupied by Starscream's Seekers during the civil war, and Sentinel Prime was imprisoned there after a disagreement with Megatron after he was kidnapped and taken to Kaon. Transformers: Exodus
Notes
- Cybertron's two (or three, or four) moons were first shown in the movie. At no point were any Cybertronian satellites seen in the first two seasons of the cartoon, making their presence in the movie a bit of a mystery. However, a "drunken" Megatron does refer to Cybertron as 'the land of the metal moon' (singular) on one pre-movie occasion. Microbots

