The Belltower

"The population here has got to be outrageous. Even if fewer than one percent died recently enough in their worlds' timelines - which don't necessarily match up with the local timeline; Shell Bell spent about seventy years here before returning to her home world and finding that only a few months had gone by - that's going to be a lot of folks. We'll want an equivalent of the Crescent for it, and a computer system installed in it to handle transit so we're not just eternally propping open one bottlenecked door to Milliways."