South End Artists open their working studios for the annual SoWa Art Walk. An opportunity to interact with the artists, purchase their work and find out how they make it. Galleries, cafes and stores open for the day. Artists at the BCA on Tremont, at 46 Waltham Street, on Wareham Street and at 450-460 Harrison at Thayer Street are participating. Free Shuttle all day. Ample Parking. Also: The Three Big Open Air Markets debut for the May-October SoWa Sundays Season: The SoWa Open Market, the SoWa Vintage Market and the SoWa Farmers Market!