Northam Burrows in Devon has an impressive coastal defence: a bank of limestone cobblestones, 2 miles long and standing more than 2 metres above high tide. It looks artificial, but the bank is natural, made by wave action over centuries.
Known as the Pebble Ridge, this is an example of a coastal boulder deposit. Longshore drift carries rocks from nearby eroding cliffs eastwards down the coast to Northam Burrows. During big storms, powerful waves carry a mixture of stones, gravel, pebbles and sand up the beach.
