Shops will be open late and more than a dozen gallery openings and special shows will take place. Go to WestChesterGalleryWalk.com for the map and list of Gallery Previews. Of special interest is the Vintage Garage Sale and En Plein Air, both occuring at the new Chestnut Street Garage — the Vintage Garage Sale on the ground floor and En Plein Air on the rooftop. Across the street is the Chester County Historical Society (225 N High St, 610-692-4800) presenting artist John Hannafin with special guest Bam Margara. The museum is also offering FREE addmission of their current exhibits throughout the day.