"Swans flocked to Svetloe - a unique lake famous for its warm underground springs that prevent it from freezing even in the harshest winter - in Russia's Altai Krai. Footage from December 21 shows the birds arriving at 'Swan Lake'. "We drove 200 kilometres to see this beauty. We were very lucky with the weather. Even though it's snowing, it's still warm. It's very beautiful, very noisy. The swans, of course, especially in flight, are delightful," said one visitor, Victoria Sycheva. Lebediny Nature Reserve ranger Alexei Soldatov explained how he cared for the birds, and fed them daily. "Last year, more than 1,200 birds were counted on the lake. This year, if there are severe frosts, I think there will be even more. <...> Every year, there are more birds for one reason: they fly away to nest in pairs and return with offspring - they have three to five chicks. The grey ones are this year's chicks," Soldatov added. He also explained how the springs meant the water temperature did not drop below +4°C. Swans remain on Lake Svetloe until March. Every year, thousands of tourists visit the site, from neighbouring regions and around the world."