Bogs are widely distributed in cold, temperate climes, mostly in boreal ecosystems in the Northern Hemisphere. The world's largest wetland is the peat bogs of the Western Siberian Lowlands in Russia, which cover more than a million square kilometres.[4] Large peat bogs also occur in North America, particularly the Hudson Bay Lowland and the Mackenzie River Basin.[4] They are less common in the Southern Hemisphere, with the largest being the Magellanic moorland, comprising some 44,000 square kilometers. Sphagnum bogs were widespread in northern Europe[5] but have often been cleared and drained for agriculture.
A 2014 expedition leaving from Itanga village, Republic of the Congo discovered a peat bog "as big as England" which stretches into neighboring Democratic Republic of Congo.