Titans Lair was once a records storage facility owned by Wayne Enterprises. Bruce Wayne allowed his sidekick and ward, Richard Grayson, the use of the empty silo during the time when Robin helped to form the original Teen Titans group.
The original one-level cavern is located beneath a cliff adjacent to the Gotham River across from Gotham City. Special emergency exits exist at the base of the cavern, which allowed the Titans the ability to come and go in secret. It also enabled Aqualad quick access to the Atlantic Ocean. After various updates, the Lair contained a concealed helipad for the Titans Helicopter as well as living quarters, cargo lift elevators, laboratories, a warehouse and a mechanic's shop.
The Teen Titans headquartered themselves at Titans Lair for a brief period of time, but left when they chose to work in a training program with Loren Jupiter.
Sometime later, the original Teen Titans disbanded for a two-year hiatus, but eventually reformed in response to an emergency distress signal they discovered coming from their long-abandoned lair.
Doctor Light (Arthur Light) had discovered their secret headquarters and sent the signal in order to bait the Titans into a trap. After suffering a narrow defeat, the Titans decided to abandon their old headquarters in favor of a new headquarters (funded by Bruce Wayne) under the Long Island disco/dance club known as Gabriel's Horn.
Years later, the Titans from the Future attempted to ensure the existence of their timeline by entering the present and corrupting the current Teen Titans group. Capturing their mentors and imprisoning them within the Titans Lair the conflict escalated with the arrival of the Titans Army which came under attack by Starro; who was operating as a Sinestro Corps member during their attack on Earth.