After being banished from South Park, Stan ends up in the middle of the forest, where he and the horse he was riding on was picked up by a small group of PETA members. Stan were brought into the PETA compound and shown around, before being permitted to stay in the compound.
The compound was later raided by P. Diddy and his crew, killing virtually all the PETA members (sans Stan).
The compound seems to be a protected area, fenced and guarded by compound members who are stationed on guard posts around its perimeter. The compound itself has simple brick houses and tents for the humans and animals to live in, surviving on hay stacks, hand-powered water pumps and small farms.