Lake Khovsgol

The colour of Khovsgol's water is its first revelation: even on an overcast day it runs from deep cobalt blue at the centre to turquoise green at the shoreline, a clarity that comes from the lake's great depth and the absence of agricultural runoff in its entirely forested catchment.

The lake is enormous by any reasonable standard — 136 km long and up to 262 metres deep — yet it feels intimate because the surrounding pine-forested mountains close in on all sides, giving it the character of a mountain sea rather than a featureless plain.

The western shore has the most developed tourist infrastructure with ger camps at regular intervals along the roadless lakeside, and the eastern shore is reachable only by boat or a multi-day horseback trek through the forest — a distinction that makes the crossing by small motorboat feel like genuine travel.

In Khovsgol province the indigenous Tsaatan (reindeer people) still practise seasonal migration with their reindeer herds, and visits to Tsaatan camps can be arranged through the ger camps at the lakeshore — an encounter with a way of life that has no parallel elsewhere in Mongolia.

The forest around the lake is primarily Siberian larch, pine and birch, home to brown bears, wolves, elk and over 200 species of birds; the combination of ancient forest, clean water and protected status makes Khovsgol one of the most ecologically significant freshwater systems in Asia.

Mid-summer on the lake has a particular quality: warm days with afternoon thunderstorms rolling down from the Sayan Mountains, the water warm enough for swimming despite the altitude, and the evenings clear and cold with the Milky Way clearly visible over the dark water.

The ice on Khovsgol forms in November and does not break up until May, and winter visits — while extreme — offer the unique experience of the lake as a frozen highway crossed by horse-drawn sledges, a scene that has changed little for centuries.

The Tsaatan (reindeer people) of Khovsgol province are one of only two remaining reindeer-herding cultures in Mongolia; they have lived in the forests of the Sayan Mountains for centuries and maintain a semi-nomadic lifestyle that is increasingly threatened by mining activity in the region and by the effects of climate change on the lichen and mosses that sustain their herds.

The lake has been a Strictly Protected Area (SPOA) since 1992, meaning that commercial fishing, motorized water sports and permanent construction are prohibited; this rigorous protection has maintained the water quality and ecological integrity of the lake at a level that is increasingly rare in Asian freshwater systems.

Swimming in Khovsgol is possible from July to September when surface temperatures reach 18 to 22 degrees Celsius at the southern end; the water is remarkably clear -- visibility extends to 8 to 10 metres -- and the underwater landscape of submerged boulders and drop-offs is as dramatic as the surrounding landscape from the shore.

The lake holds approximately 2% of the world's surface freshwater in a single body, making it one of the most significant freshwater repositories on Earth and the largest freshwater lake in Mongolia by volume.

The combination of pristine mountain lake, ancient Siberian forest, Tsaatan reindeer herders and protected wildlife makes Khovsgol a complete ecological and cultural destination.

The Blue Pearl nickname reflects both the extraordinary water colour and the relative remoteness of the site from Ulaanbaatar, which has kept it less developed than it might otherwise have been.