Ali-Sadr Cave is one of the tourist attractions of Hamadan Province. It is the world's largest cave. According to geologists, the stones of this mountain belong to the second geologic period, i.e. Jurassic Era (136-190 million years ago). Evidence from the cave indicates that Ali-Sadr Cave has been used as shelter by primitive men. Extraordinary natural patterns such as Statue of Liberty and name of Allah have been carved on the limestone walls of the cave.