The White Supremacist Compound was the hideout and methamphetamine lab for Jack's White Supremacist Gang. It contains a meth lab in a Quonset hut, club house and a pit in which Jesse Pinkman was held hostage.
After murdering Declan and his crew, the gang stole the methylamine and lab equipment they were using and set it up at their compound. Lydia Rodarte-Quayle visited the compound to inspect the production set-up and the product that Todd Alquist was able to cook in the new lab.
After their stand-off in the desert when the gang murdered Hank Schrader and Steven Gomez, stole much of Walt's money and took Jesse hostage, they kept Jesse in chains in an outdoor pit and forced him to cook meth for them. ("Ozymandias")
Jesse tried to escape the compound at one point by picking the locks on his chains and clambering out of his pit. He was caught after being spotted by a security camera and punished by being forced to witness the murder of Andrea Cantillo by Todd. ("Granite State")
When Walt returned from New Hampshire, he drove to the gang's compound under the guise of showing them a new cooking method, and successfully managed to kill all the gang members and rescue Jesse. Mortally wounded in the incident, Walt wanders around the gang's lab, before collapsing as the police arrive at the scene. ("Felina")