In the beginning of the Pleistocene Glaciation, as the climate cooled down, the alpine glaciers of the Scands began to expand. Caused by gravity, the glaciers flowed downwards covering a larger and larger land area. In Finland, the direction of expansion was from North-West to South-East. Northern Lapland was an exception, where the ice sheets advanced from South-West to North-East. During the peak of the glaciation (approximately. 20 000 years ago) the whole of Scandinavia and a large percentage of Northern Europe were covered by ice.