The Stark Tower Complex was built as a world-class financial and business facility to complement the Midtown Manhattan business district. The building was completed as a gleaming beacon of modern architecture after four years of excavation and construction. It is located in the vicinity of Manhattan's Columbus Circle approximately 10 blocks north of the Baxter Building, headquarters of the superhero team the Fantastic Four.
While initially intending to use the top three floors of the Main Tower as his state-of-the-art bachelor pad, Stark gave them over to the Avengers as their base of operations after their former base, Avengers Mansion, was destroyed. Longtime caretaker of the Avengers Mansion Edwin Jarvis was asked to resume his duties in the new location. Later, when the Sentry became a member of the Avengers, his long-hidden Watchtower appeared, integrating itself atop the Main Tower, fully integrated into the building's existing architecture. Serving as both Sentry's headquarters and as the private residences of Robert Reynolds and his wife Lindy, the 20-story watchtower is operated and maintained by CLOC (Centrally Located Organic Computer), a near-sentient computer of Sentry's own design. The lower levels of the Main Tower, along with both the South and North Buildings, are largely occupied with Stark's subsidiaries and non-profit organizations.
After the passing of the Superhuman Registration Act (SRA), Iron Man was tapped to head the task force charged with enforcing the Act. Subsequently, Stark Tower became the base of operations of the task force. The controversy surrounding the SRA broke the Avengers team apart leaving Tony Stark to form a new team, the Mighty Avengers, who continue to occupy the Main Tower's higher levels. When the Tower became the headquarters of the SRA task force, it was assigned by the government a squad of Cape-Killer guards with the call sign "Force Unit 9".
During the events of World War Hulk, a violent battle between The Hulk and Iron Man nearly caused the collapse of Stark Tower. The tower was rebuilt by Stark under his S.H.I.E.L.D. organization, making it S.H.I.E.L.D. property.
Stark Tower becomes the setting for a multi-issue conflict between humans and a murderous Skrull hunting them for sport. During the "Secret Invasion", many non-powered New York citizens, including Daily Bugle reporter Ben Urich, end up at Stark Tower. Unfortunately, it had become the hunting ground for a Skrull. He is shown killing most of the members of a design firm that had rented space in the building. Ben Urich regains control of the security shutters and the Skrull is tricked into throwing itself out a high window. It dies on impact.
When Norman Osborn took over S.H.I.E.L.D., and renamed it H.A.M.M.E.R., he also took ownership of the tower. After Osborn is removed from power following the Siege of Asgard, the tower is returned to Stark. With the Sentry's death, his watch tower disappeared from the rooftopwhere it is replaced by Heimdall's observatory as sign of solidarity between Earth and Asgard.
During the events of the Fear Itself storyline, Thing acquired a hammer. This transformed him into a being with Asgardian-like power called Angir: Breaker of Souls. Red Hulk started to fight him to protect the innocents, but got batted away by Thing. Red Hulk survived though and to try and remedy it, Thing tossed his hammer through Avengers Tower, bringing it down onto Red Hulk.
A new Stark Tower was later built on the site of the original. The structure currently acts as the headquarters of the Avengers.