This stunning ensemble of three bold concrete structures, surrounding an enormous reflecting pool (670 feet by 100 feet), houses the world headquarters of the Christian Science church. The grand Mother Church Extension (1906), facing Massachusetts Avenue, holds one of the 10-largest organs in the country, with over 13,000 pipes. The Romanesque-style original church (1894), with its rough granite facade and bell tower, connects to the rear of the extension. Named for the founder of Christian Science, the Mary Baker Eddy Library for the Betterment of Humanity opened in 2002. Step inside to experience the Mapparium, a 30-foot walk-through glass-paneled globe that represents the worldwide scope of the church's publishing activities. The library includes the Hall of Ideas, the Quest Gallery and The Monitor Gallery, with exhibits on The Christian Science Monitor, an international daily newspaper published by the church since 1908.