Some of the planet’s most captivating coils are more than just design eye candy. The Treetop Tower of Rüge, for instance, lets you explore a forest canopy. The puquios of Peru, on the other hand, were once part of a sophisticated, ancient hydraulic system. Still others, such as the Great Salt Lake’s Spiral Jetty, well, that’s eye candy for those dedicated enough to get to it. From the symbols carved into a Neolithic tomb in Ireland to a dazzling staircase in a lavish 16th-century mansion, here are 30 wondrous whorls sure to set your head spinning.