The Ali-Sadr Cave, originally called Ali Saadr or Ali Sard, is the world's largest water cave which attracts thousands of visitors every year. It is located in Ali Sadr Kabudarahang County about 100 kilometers north of Hamadan, western Iran. Because of the cave's proximity to large cities such as Hamadan, it is a highly recommended destination for tourists from all corners of the world. Tours of the cave are available by pedalos. The Ali-Sadr cave was rediscovered by a shepherd from Ali-Sadr village in which the cave is located.