Amazon just opened the second building of its new Seattle headquarters last week, but that hasn’t stopped the online retail giant from gobbling up office space all over the region.

Amazon has inked a lease at Midtown21, a 21-story office tower just a few blocks away from its new campus in the Denny Triangle neighborhood, that covers the entirety of the office space, about 365,000 square feet, the developer Trammell Crow Co. and its partner MetLife announced Monday. The building is under construction now and is scheduled to open next month. Amazon will move in next year.

Amazon’s growth continues to amaze. Last month, it announced plans to lease five floors of the old Tommy Bahama headquarters in the South Lake Union neighborhood, where Amazon first planted its flag in 2007. That came just a couple weeks after news that the online retail giant is opening a new office across Lake Washington in Bellevue, where it recently completed a lease for 354,000 square feet of office space.

All this activity comes as Amazon continues to build out its new campus. As the second building opened last week, crews were already working on the third block, which temporarily housed the company’s Prime Now rapid delivery hub. The company also has a fourth block in the neighborhood, where permit records show it is planning to build approximately 860,000 square feet of office space.

Earlier this year, Amazon Director of Global Real Estate and Facilities John Schoettler said by 2022 the online retail giant could take up close to 12 million square feet across 40 buildings in Seattle. All this space is necessary to house the company’s rapidly-growing workforce, now totaling more than 35,000 people in Washington state, and 306,000 worldwide.