Why are some of Mongolia’s lakes called 'seas'? Here’s the likely reason

Several of Mongolia’s largest lakes carry the word “sea” in their names, a distinction that may seem puzzling given the country’s landlocked location far from any ocean. The likely explanation lies in the Mongolian language itself. While the word далай (dalai) is commonly translated as “sea” or “ocean,” it has historically been used more broadly to describe a vast expanse of water. That linguistic tradition is believed to have influenced the naming of some of Mongolia’s most prominent lakes, which came to be known as “seas” despite being inland bodies of water.

Mongolia, a landlocked country in the East Asia region located between Russia to the north and China to the south, also has a distinct word for a lake: "нуур" (nuur). Many of the country's lakes officially carry this designation. One example is Lake Khuvsgul, among Mongolia's largest freshwater lakes, which is known locally as "Khövsgöl нуур" (Khövsgöl Nuur), literally meaning "Lake Khuvsgul."

Yet the lake is not known only by that name. Because of its immense size, it is also often called "Khövsgөл далай" (Khövsgöl Dalai), or "Khövsgöl Sea." The name reflects an older understanding of the word "dalai" as a reference to a large expanse of water rather than a term reserved exclusively for oceans.


The lake is known in Mongolian as Khövsgöl Nuur, which translates directly as “Lake Khövsgöl” (Khuvsgul). In some contexts, it is also associated with the term “dalai,” reflecting the Mongolian word for “sea” or “ocean” used to describe large bodies of water. This way of naming bodies of water is not unique to Mongolia. Across the world, several large inland waters continue to bear the word "sea" despite having no connection to an ocean. The Caspian Sea, the Aral Sea, and the Dead Sea are among the best-known examples.

The importance of the word "dalai" extends beyond geography. It also appears in the title "Dalai Lama," which is often interpreted as "Ocean of Wisdom." In 1578, the Mongol ruler Altan Khan conferred the title on the Tibetan Buddhist leader Sonam Gyatso. In that context, "dalai" carries the meaning of "ocean."

The word also appears in the title 'Dalai Lama,' where 'dalai' means 'ocean' in Mongolian. In 1578, the Mongol ruler Altan Khan bestowed the title on the Tibetan Buddhist leader Sonam Gyatso.

Although the use of "dalai" for certain lakes is well documented, scholars have not reached a definitive conclusion about how or why this naming convention originated. One thing is quite certain that the word 'dalai' historically denoted a vast body of water and was not limited solely to oceans. The broader meaning explains why some of Mongolia's largest lakes came to be identified with a term that is commonly translated as "sea."