Ptolemaeus Lunar Base

Ptolemaeus Lunar Base is a Federation military shipyard on Luna. It was originally a staging ground for construction of colonies at L1 and L2, but was militarized some decades after their completion and turned into a military facility. Though it's less publicly known, the old bays for storage of colony construction material have been rebuilt and now serve as one of the primary storage facilities for the Federation's 'non-standard' weapons, including nuclear arms.

Despite the name, Ptolemaeus Lunar Base does not extend across all of Ptolemaeus Crater; it is built into Ammonius, a much smaller crater in Ptolemaeus' northeastern quadrant.