Think “surfing hotspot” and it’s unlikely China’s Qiantang River springs to mind. But not only is the 285-mile river home to the Moon Festival, an annual event attracting the best surfers from around the world, it’s also the site of a rare wave phenomenon that has mesmerized tourists for centuries. Each autumn, a massive tidal bore — a wave that travels against the current — surges up the river. At thirty-feet high and traveling at 25 miles per hour, the “Silver Dragon,” as it is known, is the largest tidal bore in the world and so powerful that only a few hefty commercial boats are allowed on the river at the same time. Now a group of American surfers has launched an annual festival on the river, using jet skis to reach the bore which pounds through the city of Hangzhou. Skyscrapers can be seen looming behind the daring surfers as they ride the murky Silver Dragon, while hundreds of thousands of people stand on the banks and watch this natural phenomenon barrel past. Like the fortune cookie said: no ocean, no problem.