In the 1830s New York City badly needed fresh water to combat the spread of disease, and the Old Croton Aqueduct was built to bring it from the Croton River. Today its route is a linear state historic park through Westchester County. The park is open year-round from sunrise to sunset. The aqueduct has no parking areas of its own, but ample street parking is available nearby. There is no charge to use the trail, and walks and tours are offered; events are listed at aqueduct.org.