Abstract <p>Alternating warmer and colder periods of the Late Pleistocene caused such energy-intensive processes as the extraction of water from the ocean and its storage as glaciers on the continents. Glaciers had a profound effect on the Earth’s surface, causing the crust to sag under the extra weight or creating specific landforms through glacial exaration and accumulation. The interaction between glaciers and the crust sometimes activates high-energy secondary processes such as subglacial volcanism, a rather rare phenomenon on Earth. Subglacial eruptions lead to the formation of flat-topped mountains—tuya volcanoes, which are known to exist in only four places on Earth. One of them is the Sayan-Tuva Upland in the South Siberian Mountains. The region preserves exceptional landscapes created by late Pleistocene glaciation and volcanism, and is of real interest to geoscientists.</p>