The hill by 115th Street in Morningside Park There's a good reason why so many neighborhoods in Upper Manhattan have the word "Heights" in them—the area boasts some of the hilliest terrain in all of New York. That means when it snows, good sledding spots abound. Here, then, are uptown's five hilliest parks and their best slopes, from north to south: Morningside Park Best spots: 110th Street, 115th St and Morningside Ave and 121st Street and Morningside Ave How to get there: A