There are upwards of 800,000 lakes in Russia's Sakha Republic, many of which are found clustered in its northeastern corner. Sakha, also known as Yakutia, is the most expansive subnational entity in the world, covering nearly 1.2 million square miles (3.1 million square km) -- an area almost equal in size to India. About 40% of the republic is north of the Arctic Circle and covered by permafrost, which keeps many of its lakes frozen for 9-10 months of the year.