How to Launch a Revolution, Luna Edition.
Something like that, anyways.
There was always a chance something would go sideways, no matter the planning, but it was a tribute to their collective professional paranoia that nothing actually did go spoing!
Tycho Under, Luna
Compared to Artemis City, Tycho Under was nothing at all. But then, Artemis City was over ninety cubic kilometers, while Tycho Under was less than ten. That was still enough to support a population of nearly a million in relative spaciousness.
The limitation on size was tied directly to the unique nature of the city. The central cavern it occupied was discovered accidentally during the early years of the Colony, as a wave of mapping expeditions were sent out across the surface of the Moon. When they reached Tycho Crater the selenologists were surprised to discover an emptied magma bubble three kilometers below the central peak of the crater. Seismological readings revealed the extent of the hollow. The selenologists speculated it was formed when the original impactor created the crater over 100 million years earlier.