Grenen

A four-kilometre sandbar curling out from the top of Jutland to the point where the Skagerrak meets the Kattegat, named for its likeness to a branch. The colliding waves built it and are building it still: the reef has grown about a kilometre northeast towards Sweden over the last century, roughly ten metres a year. The currents are strong enough that swimming is prohibited. More bird species have been recorded here than anywhere else in Denmark, and birdwatchers rate it the best place in Northern Europe to watch raptors on spring migration. Porpoises and seals are common.