Mahdishahr Darband Cave - Semnan Province
Darband Cave is related to the third era of geology and is made of sedimentary rocks. Due to the large amount of lime and solutes, Stalagmite columns are abundantly observed. The first excavations in the cave were carried out by local people, and there is no any detailed information about it, but later various sports teams and climbers explored the cave, and Mahmoud Daneshvar in 1327 could reach the end of the cave. Later in 1335, another group of visitors randomly found some jewelry and objects in the cave.