Grand Central Earth Celebrate Earth Week at Grand Central Terminal with a series of weeklong events. On Fri. and Sat., visitors can stop by the EarthFair, a two-day art and entertainment festival held indoors and outdoors. Tonight from 6 p.m.-10 p.m. there's an Earth Night social networking party featuring green drinks and environmentally friendly furniture. And Giant Earth Images, a display featuring artwork by the likes of Andy Warhol and Roy Lichenstein, plays all day long in the main concourse. (Today-Sat., Giant Earth Images, 10 a.m.-8 p.m.; Earth Night, 6 p.m.-8 p.m.; free admission. Grand Central Terminal. (212) 922-0165, www.earthdayny.org).
A Walk in the Park Pack a picnic and head to Central Park for an afternoon of concerts, games, eco-crafts, park tours and planting, presented by the Central Park Conservancy. You can even get in on the action by hopping on one of the Green Fleet's bicycles and pedaling to help generate a human-powered sound system. (Sun., noon-4 p.m.; free admission. Rumsey Playfield, Central Park, enter at 72nd St. (212) 310-6600, www.centralparknyc.org).
BRONX
Go Wild! The Bronx Zoo has enough events to keep you busy all weekend long. Families can check out the Earth Expo, which showcases companies and organizations that help keep the planet a little greener, or take part in the Wildlife Conservation Society's first-ever "Run for the Wild," a 5K run on Sat. at 9 a.m. The zoo will also feature yoga, craft-making from recycled materials and one-of-a-kind animal sculptures made entirely from found objects. (Sat. & Sun., 10 a.m.-5:30 p.m.; $11-$15. Southern Blvd. at 182nd St. (718) 220-5100, www.bronxzoo.com).
Ever Green, Ever Blue Find out what you can do to help save local marine life by visiting the New York Aquarium. Families can dance until they drop to green-themed tunes by Rock the House, help create an Earth Day mural, or take in a marine life show starring a lively bunch of California sea lions. (Today, 10 a.m.-5 p.m.; $9-$13. Surf Ave. and W. 8th St. (718) 265-3474, www.nyaquarium.com).
QUEENS
Green Your Community Get outside and enjoy the fresh spring air at the Grove Hill Playground Learning Garden. Participants can plant flowers, herbs and vegetables in the community garden while they learn firsthand about conservation. (Sat., 1 p.m.-4 p.m.; free admission. E. 158th St. and Eagle Ave. (212) 360-1399, www.nycgovparks.org).