With dozens of Shoppes and 12,000 square feet, inside and 4 acres outside the Manahwkin Mart and Flea Market is a clean, modern, air conditioned facility. Great Values on new and used merchandise. Walk through shops of storefronts centered around a "turn of the century Bay ave in Manahawkin". Don't miss The Marketplace featuring speciality food and the best cheese on LBI . Dozens of concessions and entertainment. Come visit the Long Beach Island's Largest and World's Nicest Flea Market.the Manahawkin Flea Market. Manahawkin Mart is host to more than 8,000 visitors per weekend! This facility accommodates merchants offering a wide array of products/services, attracting visitors of all walks of life.