Avengers Tower formerly known as Stark Tower is a high-rise building complex located in Manhattan, New York City. Constructed by Tony Stark, the tower was powered by an Arc Reactor that makes it capable of running itself for over a year. The top ten floors were originally all devoted to research and development.
Following the dissolution of S.H.I.E.L.D., Stark made the tower the main headquarters of the Avengers. However, after the Ultron Offensive, Stark refurbished an old Stark Industrieswarehouse upstate into the New Avengers Facility for the Avengers to use as their primary base while Avengers Tower was repurposed for Stark Industries' use.
Following the Avengers Civil War, Stark sold the tower and had the valuable items and artifacts loaded onto a cargo plane for transport to the New Avengers Facility.[1]