For sure caving is one of the most exciting activity for both who has and has not experienced it. The beautiful, calm and astonishing cave environments give every visitor memorable time. Iran contain various caves in nature and beauty. The Ali-Sadr cave, the world’s largest water cave, is located in Iran, Hamadan city. Ali-Sadr attracts thousands of visitors every year. Visitors walk and ride boats along the cave to visit the beauty of this wonderful cave. Another cave for common visitors, is Daniyal cave, located in north part of Iran. With 2033 meters long, it is the second largest cave in Iran.