It's a legendary bathing spot named after Grettir the Strong from Saga lore. It's located by the seaside with breathtaking views and has a geothermal pool constructed with natural stones. It's said that Grettir himself swam from Drangey Island to the western shore and bathed in this very spot. The pool is around 39°C year-round, has dressing rooms, and there's a small entrance fee. Definitely worth a visit if you're interested in Iceland's rich history and stunning natural beauty.