Yuzhno-Sakhalinsk mud volcano is one of the largest mud volcanoes in Russia. It is located 24 km from Yuzhno-Sakhalinsk between the valley of the Alat River and the upper reaches of the Puta River. This volcano has the status of a geological monument of nature of regional significance "Yuzhno-Sakhalinsk mud volcano". The nature monument was created in order to preserve rare geological objects. The height of the flat cone of the volcano is slightly more than 300 m above sea level. In some places, gurgling griffins are visible on the surface, each of which represents a volcano in miniature.

Mud volcanoes are quite an interesting natural phenomenon. You will meet them infrequently, usually they are closely related to the tectonic activity and oil and gas activity of the earth. In Russia, mud volcanoes are found only in two regions: on the Taman Peninsula and on Sakhalin Island. In oil and gas-bearing areas, mud volcanoes emit methane, carbon dioxide, sometimes carbon monoxide and nitrogen.

The mud field of the Yuzhno-Sakhalinsk mud volcano is practically devoid of vegetation. Stunted grass makes its way only at the very edge. The field is convex upwards and slightly elevated above the surrounding terrain. It has a shape close to a circle with a diameter of about 200 meters. There are several "breathing" craters on the field. They are grouped together, not in the center of the field, but shifted to its edge. There is no noticeablepronounced main crater. There are about 10 active holes. They are tubercles, raised by 20-40 cm, with a pit at the top. Some are constantly bubbling,bubbling, others are releasing bubbles at intervals of several seconds or minutes. Gray slime slides from the craters to the edges of the mud field. This movement is not noticeable to the eye, its scale can be judged by the results — “frozen tongueslanguages of streams”, ancient and relatively recent. To the touch, the temperature of the erupted mass does not differ from the temperature of the surrounding soil. Liquid mud has a sharp salty taste and a faint smell.

The composition of the released mud of the Yuzhno-Sakhalinsk volcano is still poorly understood, therefore, it is undesirable to use this mud for medicinal purposes. The volcano itself is an interesting place to study the local flora – here, in the forests around the volcano, there are many plants listed in the Red Book of the Russian Federation.