Flea market

The Knolls Social Club, located at 25 Knolls Crescent, is having its annual fall flea market from 10 a.m. to 4 p.m.

There will be an assortment of merchandise for sale, including new and gently used books, toys and clothing, jewelry, dishes, pots and pans, kitchenware, handmade crafts, Fuller Brush products and a selection of gifts for the holidays.

For more information, call 718-796-6363.

AARP meeting

The Riverdale Chapter 1546 of AARP will meet at 12:30 p.m. at the Riverdale Presbyterian Church, 4765 Henry Hudson Parkway West.

The informative meeting is open to the public and will feature live entertainment. Refreshments will be served. For more information, call Manfred Segal at 718-549-0088.

Greenway meeting

Wave Hill, located at West 249th Street and Independence Avenue, will host a public meeting about the Hudson River Valley Greenway from 7:30 to 9:30 p.m.

Special guests include Project Manager Howie Mann, from the New York Metropolitan Transportation Council and Joshua Laird, assistant commissioner for planning and natural Resources, New York City Department of Parks and Recreation, who will present four possible routes for the Greenway through Community District 8. The meeting is open to the public.

For more information, go to www.riverdalenature.org.