Free, open-air, 4-mile (total) loop walk beginning and ending (where we will meet) at the Observatory Cottage in Draper Park, 407 Broadway, Hastings-on-Hudson, NY. Learn the history of this former marble quarry, which operated along (and under!) the Aqueduct. View the restoration of the site as a park with Hudson River views. Required: pre-registration (limited number); masks, and social distancing. Walk will be rescheduled if weather does not cooperate.