Stunning images of frozen Mongolian lake captured by Hong Kong photographer

Close to the border with Russia, at the foot of the eastern Sayan Mountains, the “blue pearl” – as it is known in this part of northwestern Mongolia – is classified as one of the 17 ancient lakes of the world, having held water consistently for more than 2 million years.

With mirror-like azure waters stretching to distant horizons under immense skies, it is also, with the exception of Russia’s Lake Vostok, considered the world’s most pristine lake.

Khövsgöl is 135km (84 miles) long and 262 metres (860 feet) deep, making it the second most voluminous body of fresh water in Asia. It is described as the “younger sister” of Russia’s Lake Baikal – the world’s largest freshwater lake by volume (and also its most ancient, at between 25 to 30 million years old) – into which Khövsgöl eventually drains, through waterways that wind 1,000km as they drop 1,169 metres over the 200km that separates them, crossing the border along the way.

In an arid land where most lakes are salty, Khövsgöl contains almost 70 per cent of Mongolia’s fresh water and it is held sacred. The Lake Khövsgöl National Park, bigger than the United States’ Yellowstone, plays host to a wide variety of wildlife, including ibex, argali, elk, wolverines, musk deer, wolves, brown bears, Siberian moose and sable.