Rock paintings were found in the Kokshashir gorge.

In mid-September 2021, in the Kok-shashir gorge of the Muzbel pass in the south-western spurs of Western Tien Shan (Tengri-Tagh) at an altitude of 2900 meters above sea level, the “Kanka expedition” with the participation of scientists from the National Center of Archaeology of Uzbekistan Academy of Sciences Gairatkhan Mukhtarov there were discovered rock paintings.

A one-line Sogdian inscription with images of several mountain goats were found here. This inscription consists of 5 letters, which can be correctly read when viewed in the mirror, was decrypted by a leading researchers of the Center Gaybulla Babayarov and Gayratkhan Mukhtarov on the basis of the Sogdian language and writing as nwprn "Nav-farn" ("new grace (owner)"). These researchers also emphasized that the inscription can be read as npprn "Naf-farn". The np "Naf" is the word for "people, community" in the Sogdian language, and can be found on the coins of Chach with Sogdian inscription dating from the 3-4 centuries AD as c'c'nnp "Chachan-naf" meaning "the people of Chach, the community of Chach".

In addition, the expression "Chachan-Naf" is also found on the silver and ceramic artefacts from Kerchevo (Russia) and China that belonged to ancient Sogdians. Thus, we can say that the Sogdian inscription of Kok-shashir was written by representatives of the ancient Chach society (Tashkent). This shows that the Sogdian language and writing was used as one of the official scripts in the Chach oasis from the first centuries AD to the eighth century, and its spread throughout the oasis extended to the mountain gorges of the Western Tien Shan (Tengri-Tagh). Prior to this time, ceramic and metal products, seals and coins with Sogdian inscriptions were mainly found in the central regions of the Tashkent oasis, especially in such ancient settlements as Kanka, Khanabad, etc.