Many people still haven’t heard of Freshkills Park, but for the past decade, it’s been the city’s most ambitious ecological undertaking. What was the world’s largest landfill has been — and is still being—transformed into NYC’s largest public park (at 2,200 acres, it’s three times the size of Central). A sprawling green salute to sustainability, the land is shaped by a combination of natural and engineered features, such as meadows, wetlands, and a creek winding throughout, as well as indigenous plant and animal life (goats have been introduced to clear stubborn weeds, and deer frolic about like it’s no big thing). Today only, the park will be open to the public for its Sneak “Peak” Festival. Be one of the first to view the site, with free guided hiking, biking, kayaking, climbing, birding, and kite flying. Public art, puppetry, and demonstrations about the park’s history will be on display, with food trucks for those who get hungry after all the outdoor exploring. Free shuttles will run between the Staten Island Ferry and the park entrance.

Sun., Sept. 28, 11 a.m., 2014