List of settlements...

* Andale
* Arefu
* Big Town
* Canterbury Commons
* Citadel
* Evergreen Mills (hostile)
* The Galaxy News Radio Building
* Girdershade
* Grayditch
* Little Lamplight
* Megaton
* Meresti Metro Station
* Oasis
* Paradise Falls
* Reilly's Rangers Compound
* Raven Rock
* Republic of Dave
* Rivet City
* Temple of the Union
* Tenpenny Tower
* Underworld
* Vault 101
* Vault 112/Tranquility Lane
* Warrington Station

You were 19 off...
and I don't think there is a single city. Makes sense that there are lots of smaller settlements.

I would build a large re-inforced wall around the hubris comics building and fix up the buildings. If I need supplies, open the gate and go through hubris comics, then you are almost at the caravan route.