Bought by Henry James Olsen as a wedding present to his wife, Chloe Sullivan. After Olsen's death, Chloe turned the loft apartment into the new headquarters for Green Arrow's team. Using fonds from Queen Industries, Dr. Emil Hamilton installed an advanced computer system in the apartment.
Following the event known as "Contact", the organization decided to set up an outpost on the Moon. The loft apartment, along with the rest of the building, was ultimately destroyed in the battle against the Monitors.
After the battle, the city of Metropolis constructed Liberty Park, where the Watchtower building once stood. They also raised a statue in the park of Superman, Green Arrow, Martian Manhunter, Batman, Red Tornado, Wonder Woman and the Green Lantern: the newly formed Justice League.
- After Tess Mercer broke into Watchtower, Oliver Queen had his company place a Watchtower Orbiter into space.
- The exterior of the building is the Sun Tower (digitally enhanced) in Vancouver.