The snaking Schuylkill River bisects this 9,200-acre greenspace − bigger than New York's Central Park and, in fact, the largest city park in the country. From the earliest days of spring every corner is thrumming with activity − ball games, runners, picnickers, you name it. The enthusiasm is catchy and you'll certainly want to join them. Runners will love the tree-lined, riverside trails, which range from 2 miles to 10 miles in length.