The term West End was not used until the garages were torn down and the area around the Park Hyatt was developed, south and east of Rock Creek Park, west of 22nd St, north of M and L Sts. The Marriott predates that by many years. I believe technically the Marriott is actually in the Dupont Circle neighborhood. When I lived on N St we always referred to the neighborhod as Dupont Circle, and Badlands, which was on 22nd south of P St, was considered in Dupont Circle. IIRC, everything east of 22nd St was considered Dupont Circle.