I've heard of this place, a whole city wiped out in a single day by the Holy Nation. They roasted the head noble alive in the name of Okran and carted the youngsters off to Rebirth...
Yeesh. I mean, I hate nobles as much as the next guy but...
But...
Actually, he probably deserved it.
— In game dialogue
Bast was once a city within the United Cities, now it is only ruins. Bast was recently destroyed by the Holy Nation. The only residents in Bast are UC affiliated squatters living in the ruins. There are two intact houses, one occupied by the squatters and the other one abandoned. The only loot in Bast is junk and common materials with some chance of Backpacks or Camp Beds in the intact houses.
Bast is the starting location for the guy with a dog game start. It can otherwise be discovered by exploration or by acquiring and reading the Map of the United Cities (Central Territories).
Tips
The Prisoner Cages around the city inside can be a good way to train Lockpicking skill.