Lake Baikal

Lake Baikal, the world's oldest and deepest freshwater lake, curves for nearly 400 miles through south-eastern Siberia, north of the Mongolian border.

It lies in a cleft where Asia is literally splitting apart, the beginnings of a future ocean.

Geologists say Baikal today shows what the seaboards of North America, Africa and Europe looked like as they began to separate millions of years ago.

More than 5,000 feet deep (1637m) at its most profound, with another four-mile-thick layer of sediment further down, the lake's cold, oxygen-rich waters teem with bizarre life-forms.

One of those is the seals' favourite food, the golomyanka, a pink, partly transparent fish which gives birth to live young. Geologists estimate that Lake Baikal formed somewhere 20-25 million years ago, during the Mesozoic.

Surrounded by mile-high snowcapped mountains, Lake Baikal still offers vistas of unmatched beauty. The mountains are still a haven for wild animals, and the small villages are still outposts of tranquillity and self-reliance in the remote Siberian taiga, as the forest is called.