The CTU Los Angeles building in West Los Angeles was the office of the Counter Terrorist Unit's Los Angeles domestic unit. It was designed to maximize the efficiency and efficaciousness of combating terrorists for a highly-trained corps of agents and analysts. ("Day 1: 5:00am-6:00am", "Day 2: 9:00am-10:00am") Following Day 3, the agency relocated to a second building in an undisclosed location, where it remained for several years. ("Day 4: 7:00am-8:00am", 24: The Ultimate Guide)