The Carlyle District is one of the newest parts of Alexandria. It looks particularly modern as it directly neighbors Old Town Alexandria. The Carlyle District is a 76.5 acre development in Old Town Alexandria. This modern district includes a complex of offices, hotels, including The Westin Alexandria and retail space. It is home to U.S. Patent and Trademark Office, the Federal Courthouse, as well as condo communities such as Carlyle Towers.