This weekend the Maryland Historical Society is screening "Maryland on Film III," two and a half hours of footage exploring the geography of our state. The screening includes some archival gems: a 1961 meditation on screen painting; a documentary about Baltimore’s Memorial Stadium; and “Little Castles,” a 1997 film about Formstone, the fake stone found on so many Baltimore rowhouses. Joe Tropea, Digital Projects Coordinator at the Maryland Historical Society, joins us to discuss the event. And Skizz Cyzyk, director of “Little Castles,” fills us in on the history of Formstone.