A stage for the Reaping was built among the abandoned goat farm turned into an art center. See photos of the stage at the hob and the goat farm on yelp.
Rick, T-Dog, and Daryl head to the building where the Vatos are holed up in episode 1x04 "Vatos".
The gang breaks camp and prepares to drive out of the city in episode 2x01 "What Lies Ahead".
Source: The Walking Dead Map