Most of Dorset's coastline is part of the Jurassic Coast, a World Heritage Site, which stretches for between Studland and Exmouth in Devon. This coast documents the entire Mesozoic era, from Triassic to Cretaceous, and is noted for its geological landforms. The Dorset section has yielded important fossils, including Jurassic trees and the first complete Ichthyosaur, discovered near Lyme Regis in 1811 by Mary Anning. The county features some notable coastal landforms, including examples of a cove (Lulworth Cove), a natural arch (Durdle Door) and chalk stacks (Old Harry Rocks). Jutting out into the English Channel at roughly the midpoint of the Dorset coastline is the Isle of Portland, a limestone island that is connected to the mainland by Chesil Beach, a long shingle barrier beach protecting Britain's largest tidal lagoon.