In pictures: Crossing the world's deepest lake

News imageOleg Boldyrev Ice on Lake BaikalOleg Boldyrev

Lake Baikal, the world's deepest, offers astounding views along its shoreline - and winter tours of its frozen expanse have become increasingly popular.

With some trepidation, Oleg Boldyrev walked, and even rode, across the multi-coloured ice.

News imageOleg Boldyrev Lake Baikal with bare treesOleg Boldyrev
The giant lake creates its own climate - and winter around Baikal normally starts later than elsewhere in eastern Siberia. In late December, the lake finally freezes over - but there is very little snow until mid-January.
News imageOleg Boldyrev Huge rock surrounded by blocks of iceOleg Boldyrev
Olkhon, the largest island in the lake, is a popular tourist destination, when Covid restrictions allow.
News imageOleg Boldyrev Close up of a man's shoes stood on frozen lakeOleg Boldyrev
Soon, the ice is thick enough to walk on - and even for some lighter cars to drive. In February, the ice road from the mainland to Olkhon Island opens for a short period, depending on the thickness.
News imageOleg Boldyrev Close-up of sharp slabs of IceOleg Boldyrev
Images of the ice have drawn lots of interest on social networks.
News imageOleg Boldyrev An abandoned bike lying on the frozen lakeOleg Boldyrev
A bike with studded tyres is one of the ways to explore this frozen expanse.
News imageOleg Boldyrev Two men skating on the frozen lakeOleg Boldyrev
Skating is also popular.
News imageOleg Boldyrev A long crack in the middle of the lake extending out of shotOleg Boldyrev
The lake offers many miles of perfectly smooth ice. First-time visitors may be taken aback by the massive booms and cracks as it expands and contracts, in the daytime. This is normal, locals say, but watch out for larger openings.
News imageOleg Boldyrev Paper thin layers of ice protruding from the surfaceOleg Boldyrev
The ice is never still. Massive pressure causes ruptures and elaborate combinations of paper-thin and rock-heavy layers protrude from the surface.
News imageOleg Boldyrev A single block of ice with a blue tintOleg Boldyrev
Baikal is known for extremely clear water.
News imageOleg Boldyrev View of blocks of ice submerged in the lakeOleg Boldyrev
It produces hundreds of different patterns of multi-layered cracks or bubbles.
News imageOleg Boldyrev close up of ice sculptures hanging off a cliffOleg Boldyrev
On the rocky shore, winter creates elaborate ice sculptures of its own.

All photographs courtesy Oleg Boldyrev.