Dena
Dena (in Luri and ) is the name for a sub-range within the Zagros Mountains. Mount Dena, with length and average width, is situated on the boundary of the Isfahan, Kohgiluyeh and Boyer-Ahmad and Chaharmahal and Bakhtiari Provinces of Iran. Mount Dena has more than 40 peaks higher than . With an elevation of 4,409 metres above sea level, Qash-Mastan is the highest peak in the Dena Range and in the Zagros Mountains in general. Another known peak in this range is Hose-Daal close to the city of Sisakht, to the north of Yasuj. Annual precipitation in  Mount Dena ranges from and various rivers including a branch of the Karun rise in this range. Geologically, Mount Dena is located in the Sanandaj-Sirjan geologic and structural zone of Iran and is mainly made of Cretaceous limestone. On 18 February 2018, Iran Aseman Airlines Flight 3704 crashed into Mount Dena, killing all 65 people on board.