Lake Baikal in Siberia has become a top destination for Russian and foreign tourists. But many fear the influx of visitors and their garbage is imperilling it and there is deep mistrust over the Putin government’s efforts to manage the issue. Siberia’s Lake Baikal is intensely cold, wild and uniquely beautiful. Practically free of sediment and impurities, its ice has the clarity of a sheet of glass. The first step you take on the frozen surface, you fight the sensation that you might crash through into some of the world’s coldest water below. In fact, the ice is deceptively thick — more than a metre — and sturdy enough to support a cement truck. “When they get here, people are amazed and say, ‘Why didn’t we come here before?’ ” said Igor Pobotkin, one of the many tour guides navigating the lake.