Jut­ting out into the Øre­sund Sound, the Kas­trup sea bath has been open to Copenhagen’s sea-swim­mers since 2004. Despite the Nordic lat­i­tude, the sea here can be sur­pris­ing­ly warm – espe­cial­ly since the cir­cu­lar shape of the Søbad is designed to keep the wind off. Of course, this being design-mad Den­mark, it looks great too.