This coast shows excellent examples of landforms, including the natural arch at Durdle Door, the cove and limestone folding at Lulworth Cove and a tied island, the Isle of Portland. Chesil Beach is a fine example of both a tombolo (a deposition landform in which an island is attached to the mainland by a narrow piece of land such as a spit or bar) and a storm beach (a beach affected by particularly fierce waves). The site has stretches of both concordant and discordant coastlines. Due to the quality of the varied geology, the site is the subject of international field studies.