Like seriously, from a lore perspective it makes very little sense. Vault-Tec built a total of 122 Vaults, why would they build so many Vaults right outside the exact same city. Yeah, I know that Vault 13 and Vault 15 were relatively close to one another, but it was at least a couple days walk between them and both were hidden high up in a mountain range. New Vegas vaults however, seem to be completely nonsensically placed. Like seriously, you've got 2 in the middle of the exact same city(3 and 21), 2 located around Red Rock Canyon(19 and 22), one literally just outside of Vegas(11) and one just outside the next town over(34) If we were judging by IRL distances, you could probably walk from any Vault to the next nearest Vault, and treat it like a day trip. What would be the practical advantage, if any, of placing so many Vaults in such close proximity to one another? Especially if there's only 122 being commissioned. EDIT: Accidentally put 19 twice.