Work is underway on the first structures in downtown Konterra, a planned mixed-use district in Prince George’s County that has been decades in the making.

The Gould Property Co. has started in on the townhome portion of the 400-acre downtown district, which falls in the center of its 2,000-acre census-designated region between Beltsville and Laurel, Maryland.

Gould executives on Thursday held a groundbreaking ceremony to celebrate the beginning of that first phase, which includes more than 200 townhomes being built by Caruso Homes.

“This is a beginning. It’s exciting. It’s a continuum, and it will remain like that for many years,” Gould Property Chairman Caleb Gould said at the groundbreaking. “We’re starting with the residential program so we can have rooftops in place and all of that to attract the very best retail and corporate tenants.”

The townhomes are set to start delivering in the fall. At full build-out, the 400-acre Konterra Town Center East is slated to have 1.5M SF of retail, 3.8M SF of office, 600 hotel rooms, and 4,500 homes and apartments. The full region is planned to have 8.5 miles of parks, trails and public plazas.

Purchased by the Gould Property Co. in the early 1980s, the 2,000-acre Konterra site was a sand and gravel mining site beginning in the 1930s.