Amazon has gobbled up another big chunk of land in Seattle’s Denny Triangle neighborhood, where it could build a fifth skyscraper as part of its new campus north of downtown Seattle.

Property records filed Wednesday with the King County Department of Assessments show Amazon affiliate Acorn Development paid $19.2 million for a half block along Seventh Avenue between Blanchard and Bell streets, across the street from the recently opened Day One tower.

It is unclear what Amazon plans to do with the property. Neither Amazon nor any of its affiliates have filed for permits for the site with the city of Seattle.

The seller, Clise Properties, is a long-time landholder in the Denny Triangle neighborhood, and through multiple transactions totaling more than $259 million, sold Amazon the first four blocks it is developing there.

The Puget Sound Business Journal reported on the deal earlier today. The purchase isn’t a big surprise as Amazon had an option to buy the site. Amazon also has options on another half block across the street from the most recently purchased site and a full block at the southeast corner of Dexter Avenue and Denny Way.

Last month, Amazon opened the new Day One tower, the second block of its headquarters campus. A trifecta of glass and steel orbs share the block with the new tower and are expected to open in late 2017 or early 2018, GeekWire previously reported. They will combine a retail hub, office space for Amazon employees and an indoor forest.

The second tower opening came about 11 months after Amazon employees started moving into the first building in the Denny Triangle neighborhood, the 36-story Doppler tower. A third block, which temporarily housed the company’s Prime Now rapid delivery hub, is under construction now. 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.