I'm not sure where to put this, so I'll just put it here, as this is purely just trivia. The "abandoned mental hospital" which Billy and his gang use as an "office" is, in fact, an abandoned mental hospital. It's located on Bull Street in Columbia, SC, where the film is set. While the grounds are officially closed to the public, there's nothing preventing you from driving onto the campus and seeing the buildings featured in the movie. There's an existing clinic still operating at the very rear of the grounds, which still treats clinical patients, though it's strictly in an outpatient manner; no patients are housed on the grounds anymore.
I'm not sure where to put this, so I'll just put it here, as this is purely just trivia. The "abandoned mental hospital" which Billy and his gang use as an "office" is, in fact, an abandoned mental hospital. It's located on Bull Street in Columbia, SC, where the film is set. While the grounds are officially closed to the public, there's nothing preventing you from driving onto the campus and seeing the buildings featured in the movie. There's an existing clinic still operating at the very rear of the grounds, which still treats clinical patients, though it's strictly in an outpatient manner; no patients are housed on the grounds anymore.