First-class amenities and services make 425 Mass apartments a place you'll be proud to call home. Located in the Mt. Vernon Triangle, 425 Mass is downtown Washington DC's first smoke-free apartment community. Spectacular views of the Washington Monument or the Capitol are complemented by sleek design, upscale fixtures, high ceilings, rooftop pools with private garden retreats and resort-style lounge areas along the D.C. skyline. The Capitol, K Street, Penn Quarter, Chinatown, Judiciary Square and Gallery Place are right outside your door.