Atlantic Puffin Colony — Látrabjarg Iceland

Látrabjarg — Iceland's westernmost point, a 14-kilometre basalt cliff rising 440 metres sheer from the North Atlantic — hosts the world's largest Atlantic puffin colony: 3–4 million puffins nesting in burrows along the clifftop in a density that lines every metre of the cliff edge with nesting birds at arm's reach from the unfenced clifftop path. The puffin's complete tameness — bred from millions of years without land predators and 1,000 years of Icelandic non-hunting — allows visitors to sit on the cliff edge with puffins standing at 30 centimetres, and the combination of the Atlantic Ocean 440 metres below, the cliff face alive with nesting birds, and the puffins' comical landings (flying fast, braking badly, often tumbling on the clifftop) creates one of the world's finest seabird encounters. The cliff also hosts razorbills, guillemots, and fulmars in their millions, making Látrabjarg the finest seabird cliff in the North Atlantic.