When in need of elbow room, Philadelphians head for Fairmount Park, whose 8,500 acres make it the largest landscaped city park in the world. Deemed by many Philly dwellers to be their own backyard, Fairmount beckons with a wide range of pleasures. Joggers, walkers, and bicyclists consider it prime territory. Along Kelly Drive stand the Victorian houses of Boathouse Row, headquarters of the rowing clubs that make up what's called the "Schuylkill Navy." The Mann Center for the Performing Arts hosts open-air concerts in summer. Children flock to the Philadelphia Zoo. Many people are also drawn to the centuries-old houses that dot the park. Here you can also find the noted Greek Revival Fairmount Waterworks.