The neighborhood is roughly bounded by Columbus Avenue and the Boston neighborhood of Roxbury to the east, Ruggles Street to the northeast and the Olmsted designed Riverway/Jamaicaway, and the town of Brookline to the west. The Historic District was designated by the Boston Landmarks Commission in 1985 and is roughly bounded by Smith Street, Worthington Street, Tremont Street (to the south), and Huntington Avenue (to the west). The Mission Hill neighborhood is immediately north of the Boston neighborhood of Jamaica Plain. It is served by the MBTA Green Line E branch and the Orange Line, and is within walking distance of the Boston Museum of Fine Arts and the Gardner Museum. "The Hill" overlaps with about half of the Longwood Medical and Academic Area, home to 21 health care, research, and educational institutions which together provides the largest employment area in the City of Boston outside of downtown Boston. Due to these adjacencies, the neighborhood is often struggling with institutional growth taking residential buildings and occupying storefront commercial space. Recent years have seen new retail stores, restaurants, and residential development giving the neighborhood a stronger political voice and identity, as some of the educational institutions have made commitments to house all or most of their about 2000 undergraduate students in newly erected campus housing, including several new high-rise dormitories. People aged 20 to 24 account for 32% of the population currently living in Mission Hill.