From Upper Marlboro via Pennsylvania Avenue (Route 4)
Follow Pennsylvania Avenue, towards downtown Washington.
Cross the Anacostia River (John Philip Sousa Bridge).
Take the Southwest Freeway Exit (Southwest Freeway turns into I-395).
Continue on Southwest Freeway (Route I-395).
Exit onto Maine Avenue. Continue on Maine Avenue to Independence Avenue. (Maine turns into Independence).
Continue on Independence Avenue.
Bear Right onto 17th Street (at the Washington Monument).
Continue on 17th Street (17th Street turns into Connecticut Avenue). Continue on Connecticut Ave until you reach the 3000 block. The National Zoo will be on your right at 3001 Connecticut Avenue.
