Ashburn, Va.
The Howard Hughes Medical Institute, based in Chevy Chase, Md., purchased the 281-acre Janelia Farm in December 2000 with plans for a large research campus on the property. Three office buildings and a Normandy-style mansion already exist at the site, which can support more than 2.5 million sf of space. The biomedical company is based in Chevy Chase, Md., where its headquarters will remain.