It is situated at the edge of Baysun-Tau mountain ridge, the southern spur of the Gissar Range, in the southeast of the country.

[2][3][4][5][6][7] The cave developed in the covered karst of Upper and Middle Jurassic limestones, in monoclinal strata, in the preserved wing of an anticline.

Contrary to most limestone caves it was not formed by water precipitation penetrating from the surface but, as the soluble rock is covered by insoluble strata, by condensation.

This phenomenon was referred to as boybuloq, a fusion of the words boy and buloq, meaning "rich spring" in the Uzbek language as well as in Tajik.

[10][11] The cave was known to local people since ancient times, because from its entrance a stream of water flows down the slope of the otherwise very arid mountain landscape.

[14][15][16][10][17] Young men from Dehibolo tried to find Mustafo in the cave on several occasions that summer and in the following years but to no avail.

[10][15] Not only Boybuloq cave but most other caves in the area are a long sequence of tight passages which are difficult to pass, and where possibilities for help or rescue operation are very limited,[1] as described by Sergej Kuklev, a member of the SGS team: I asked Ilija, trying to speak as calmly as possible, how, in his opinion, would it be more convenient to get through the tight meander, top or bottom?

The caving suit, torn in all possible places, didn't let go, so I had to stop to take a breath ... Only God or his/her own might can help a person which got stuck in Boybuloq – two people together just do not fit in a tight corridor.

On one of previous expeditions it happened that a caver fell off a rope in a pit and, flying 17 meters, broke both legs.

[23] As can be seen from the above map this international participation in discoveries was reflected in the naming of three substantial cave sections: the Italian, English and Russian tunnels.

[17] The spring is situated 130 m below the terminal cave siphon while the horizontal distance is 7 km, and so the connecting passages are most likely submerged.

[26] During the 2021 SGS and ASU expedition a survey team mapped the upwards extending tunnels in the New branch of the cave, explored in 2016.

Survey data showed that the highest point achieved, where the tunnel narrows into an as yet impassable hole with very strong air current, is situated 272 m above the cave entrance.

They discovered several closed loops, of a chimney which led to a horizontal tunnel, ending with a pit that brought them down into the already known part of the cave.

At the end of expedition they climbed a 170-meter high chimney, wide enough, which continued with a tunnel, presumably leading in the direction of the Višnevskij cave.

They climbed a few steps and chimneys and in one of them discovered a narrow tunnel which continued upwards in the direction of the top of the Chulbair ridge, to the wall on its eastern side.

On the last day of the expedition they measured the altitude of the last point reached with an altimeter considerably extending the amplitude of Boybuloq.

[6][7] 2015 In the year of the death of Aleksandr Sergeevič Višnevskij, leader of SGS expeditions to Boybuloq from 1988 to 1992 and from 1995 to 2008,[28] a SGS and ASU search team of 7, led by Vasilij Samsonov from Orenburg, methodically examined the 3 km long section of the 150–200 m high wall which forms the edge of the ridge above Boybuloq.

[5][29] 2016 A team of 7, 4 Russians and 3 Italians (La Venta speleo club), from the Baysun-Tau 2016 expedition, worked in the cave.

They followed the draught, and after a series of narrow passages, vertical and horizontal, which required widening, descended into a slightly wider meander with a small stream at the bottom.

After a brief acclimatization they set up the tent underground Camp −168 from where Sergej Terehin and Artur Abdjušev pushed their way through the cave till the siphon at −735 m, in a day-and-night non-stop sortie.

Another camp, of hammocks, was set up, the new part is a corridor, on average 50 cm wide, with a stream, into which 4 tributaries (unexplored) flow.

[5][31] [9][32][33][34] 2019 It was difficult to assemble the expedition as there was no clear continuation, especially not around the siphon but, when cavers from Moscow and Irkutsk also joined the SGS and ASU team, a group of 15 gathered.

The surface camp was set up in a proven location near Lunnaja cave, and a team of four: Evgenij Sakulin, Petr Kovešnikov, Anastasija Janina and Andrej Minogin departed to the bottom, to set a Camp Siphon there and to try to find a continuation in the ascending tributary at −600 m. Yet on the very first day at the bottom Evgenij and Anastasija managed to crawl through a narrow, half flooded passage and reached a meander behind the siphon.

Other plans were scrapped and the team, reinforced with Evgenij Rybka, Vasilij Samsonov and Vadim Loginov (there was a phone connection from the camp to the surface), set off to the new part.

It was dry, the ceiling gradually lowered, the tunnel turned to a crawl, solid floor was replaced by clay, it got wet.

The Višnevskij cave continued, after the terminal point reached in 2019, with a series of small pits, followed by a 30 m shaft.

After examining other options, the expedition managed to decrease the intercave distance to 70 m, between the two meanders in both caves, at approximately the same altitude above sea level, both still too narrow to pass.

[43] The possibility for achieving greater depths is however limited as the cave entrance elevations in the relevant limestone areas, the Arabika and Bzyb massifs, rarely surpass 2300 m (top peaks are Mt.

[40][45][46][47] All these facts considerably increased the attention, paid to Boybuloq, to Uzbekistan, and to central Asia, in the speleo world.