Hollis Flea Market Largest Open Air Flea Market in NH. We have 400 + vendors, spread over 15 + acres, large and diverse crowd of shoppers. Open on Sundays April-October 6:00am-- Hollis, NH Other Attractions Silver Lake State Park Hollis, NH State Parks Brookdale Fruit Farm, Inc Hollis, NH Agriculture Hollis Woman's Club Hollis, NH Other Attractions Hollis Woman's Club Hollis, NH Other Attractions