Party on Park returns this weekend. Photo: Uptown Grand Central Party on Park in East Harlem, Dia de Muertos at El Museo—plus more fun things to do this weekend in Harlem and beyond. Open House New York Weekend Friday, October 16-Sunday, October 18 FREE Various locations Here's your chance to go behind the scenes at 3,000+ gems across the city, including uptown wonders like the Mount Morris Fire Watchtower and the Historic Cottage at Fort Tryon Park. Other fun drop-in events