It's often said Iceland has everything the world has . . . but only one of them. Nowhere is this more true than Nauthólsvík, where runoff hot water from the city's geothermal heating system is pumped into the ocean through a beach of imported yellow sand. The ocean is still cold but swimmable, and Icelandic families flock here on warm days to sunbathe and splash around in the almost-hot tubs. The novelty can wear off quickly, and the view isn't much to speak of. Kaffi (Cafe) Nauthóll is close by, and you can rent towels or store valuables for 200kr ($3.20/£1.60); coffee, soda, ice cream, and hot dogs are on offer all day.