A convoluted coast

Shark Bay, at Australia's westernmost point, is a fine illustration of the fractal nature of coastlines. The bay's two main basins are outlined by two large peninsulas, each with its own little peninsulas, which have their own littler peninsulas, and so on. Add shifting tides to the mix and you have a metrological mess on your hands—in fact, to truly measure a coastline is impossible. But estimates can be made: By most rough measurements, Shark Bay's complicated coast clocks in around 930 miles long.