Dogger Bank is a large sandbank in the North Sea. It lies about 100 kilometres (62 mi) from the coast of England. It is about 260 kilometres (160 mi) long and 97 kilometres (60 mi) wide. On average, the North Sea is 94 metres (308 ft) deep. The average depth in the area of the Dogger Bank is 30 metres (98 ft), at the shallowest place the water is only 13 metres (43 ft) deep. During the last ice age, it was sometimes an island and sometimes a land bridge connecting Britain and mainland Europe.