Children will explore the materials that buildings are made from and learn about the decorations used on buildings during the past 200 years at the Geneva Historical Society's History Mysteries: Building Detectives. Participants use detective skills to spot the many styles and personalities of buildings in Geneva, and then build structures out of recycled containers. Weather permitting, the program will include a walking tour of South Main Street. History Mysteries: Building Detectives will be held from 1 until 3 p.m. on Thursday, July 18, at the Geneva Historical Society. The program is geared toward children 6 to 10 years and costs $2 per child for Geneva Historical Society members, $3 per child for non-members. Reservations are required and the registration deadline is July 15. For reservations or more information, call the Society at 789-5151.