When? Graffiti Alley is open 24 hours a day for viewing. Artists can paint on the wall daily, except between 5 pm and 1 am, Wednesday through Saturday. Where? Richard B. “Rico” Modica Way at 565-567 Massachusetts Ave., Cambridge. Take an MBTA Red Line train to Central Square. How much? Why should I go? This 80-foot walkway, known as “Graffiti Alley,” connects City Parking Lot 5—home to Starlight Square—to Massachusetts Avenue in the heart of Central Square. It’s one of only two places in the Greater Boston area where artists can legally post graffiti art. Rookie artists often paint smiley faces along with their names, while the more advanced create full-fledged works of art.