Spanning more than 800 acres (3.24 square kilometers) in the heart of Manhattan, Central Park encompasses a diverse landscape of rolling fields, walking trails and tranquil waterways. Designed in the mid-19th century by Frederick Law Olmsted and Calvert Vaux, the park today is the centerpiece of the City's public parks system. Among its landmarks are Wollman Rink, the Central Park Zoo and the Friedsam Memorial Carousel—great for kids of all ages. Sheep Meadow and the Great Lawn, meanwhile, offer sprawling expanses where visitors can relax and enjoy the outdoors. In the summer, the Great Lawn plays host to free shows courtesy of The Metropolitan Opera and the New York Philharmonic, while the Delacorte Theater is the location for Shakespeare in the Park. Elsewhere in the park, Rumsey Playfield is the site of SummerStage, a free performing arts festival featuring music, dance, film and more.