Deep in the mountainous region of Siberia, Russia, north of the Mongolian border is where you'll find a lake of superlatives.

Not only is Lake Baikal the world's deepest and oldest (25-30 million years old), but it's also the largest freshwater lake and one of the clearest on earth.

Ironically, this massive late is where you'll find the world's smallest seal; the Baikal seal.

Scientists believe the seals reached Lake Baikal by travelling up river systems that connected the lake to the Arctic Ocean during the Pleistocene era. Photo / Dmitry Kokh

The lake's remote location and tendency to freeze over for five months of the year may dissuade most people from paying a visit, but for wildlife photographer Dmitry Kokh, the challenging conditions inspired him to go and capture the lake and its little inhabitants.

Although, getting to the lake isn't even the hardest part according to the Russian photographer who had attempted a trip in 2019. Rather, it's the timing.

"The time of year and age of the seal is crucial," Kokh told Herald Travel. "They can't be too young because they'll still be too dependent and stay close to their mother, and they can't be too mature as they'll be too shy and scared.

"That perfect in-between teen age is optimal for photography as they are more curious and interested".

Kokh's 2019 trip was unsuccessful but in 2022 he timed it perfectly.

The Baikal seal's large eyes help them drive up to 100m deep to forage for fish. Photo / Dmitry Kokh

Female Nerpas give birth in March and while newborn pups are covered in white fur, they cannot swim, which can create stress for the mother and baby if humans are nearby.

However, by April when Kokh visited, the pups' fur had turned grey and they were ready to explore the wonderful world beneath the ice.

The seals tend to grow up to 1.3 metres long. Photo / Dmitry Kokh

The result, we must admit, is pretty adorable. Unsurprisingly, Kokh said photographing the seals was "a pure joy"

"They are fun, friendly, curious and very photogenic. So the experience is almost always rewarding," he said, adding that it beat a day in the office.

Baikal seals are the only true freshwater seal in the world. Photo / Dmitry Kokh

As for how he managed the underwater temperature, which can drop to −19 °C in winter, Kokh used a combination of expert equipment and a classic European trick.

"You need temperature-appropriate gear and must prepare safety-wise, but the short answer is that the excitement and adrenaline keep you warm! Vodka helps too!"

Kokh has photographed many fascinating creatures in unusual places, including polar bears who took over an abandoned meteorological station on an island between Russia and Alaska.