Just across the Main Street and Acosta bridges from downtown Jacksonville is San Marco, and it’s sizzling hot. High-rise condo construction abounds along the St. Johns River as people continue to clamor for water views. The area’s popular shopping district, named San Marco Square after St. Mark’s Square in Venice, is at the intersection of Atlantic and San Marco boulevards. It boasts boutiques, art galleries and fine dining restaurants. Theatre Jacksonville, the country’s longest-running community theater, has called the square home for almost 90 years. But San Marco is not known solely for its commercial side — not by any means. It also has a handsome residential neighborhood that dates to the early 1920s. The stately homes and riverfront mansions range in style from Georgian to Art Deco; nowhere are those styles more prevalent than on winding River Road.