Central Park is a 17-acre (69,000 m2) municipal park maintained by the city of Louisville, Kentucky. Located in the Old Louisville neighborhood, it was first developed for public use in the 1870s and referred to as "DuPont Square" since it was at that time part of the Du Pont family estate. During the Southern Exposition in 1883, 13 of the park's 17 acres (69,000 m2) were temporarily "roofed in" and used to showcase Thomas Edison's light bulb, one of the first large-scale public displays of the light bulb in the world. In 1885 the park was unroofed, and was instead used as an outdoor exposition, with an Edison designed electric trolley line transporting visitors around the park to see such sites as a roller coaster, bicycle trails, and an art museum surrounded by a lake. By 1904 the entire Du Pont family had moved to Wilmington, Delaware, so they sold the park to the city of Louisville for $297,500. The city enlisted famed architect Frederick Law Olmsted, the man who designed New York City's Central Park and had already designed an entire park and parkway system for the city of Louisville, to plot the new park. Olmsted had a large open air shelter with a colonnade built on top of the hill where the art museum had once stood, along with a wading pool and athletic fields on the side. The original walking trails were kept in place.