Fallingwater is a Frank Lloyd Wright masterpiece, now maintained by the Western Pennsylvania Conservancy. The structure of stone, concrete and glass is a staggering multi-level home cantilevered over an actual waterfall. The regular tour lasts about 45 minutes, the in-depth tour about two hours. There is also a children's tour, and a three-hour combination tour of the home and surrounding landscape. Fallingwater is closed during Jan-Feb for maintenance. Advanced reservations are required – book regular tours at least 1 week in advance, in-depth weekday tours two weeks in advance, in-depth weekend tours 4-6 weeks in advance. Children must be 6 years old to accompany an adult on a regular tour, 9 for an in-depth tour. Younger children may stay at the supervised Child Care Center for $2/hour per child.