Developers are beginning to see the potential in old post offices across the U.S.

The buildings, which were once massive, bustling places of business in prime downtown locations, are being converted into creative office spaces and mixed-use developments. As digital communication continues to lead in both professional and private lives, the need for physical mail has decreased substantially, leading the Postal Service to sell off approximately 32 properties per year for the last seven fiscal years, the New York Times reports.

Chicago’s main post office has remained vacant since 1997 but will soon be transformed by 601W Cos. into a 2.8M SF office building with open-concept, collaborative spaces aimed to attract millennials. The sheer size will allow for the creation of a full neighborhood complete with a large gym, a quiet working area that takes inspiration from a university library and a Gatsby-inspired lounge, which blends with the stone floors and decorative panels in the space.

In Manhattan, Related Cos. and Vornado are revitalizing the James A. Farley Building. While the Postal Service will continue to use the third floor for its workers, the building's second through fifth floors will cater to a new set of office tenants while the first floor and concourse level will house new retail tenants and offerings.

In Houston, the former Barbara Jordan Post Office in the downtown core will be converted into a creative arts hub. A former warehouse will include a space for shops, artists and food purveyors on the ground level, and office areas for creatives on the second floor, while the former five-story office building will soon be transformed into a hotel.