Should you find yourself in Lerwick, Scotland, on the last Tuesday of January, you’ll witness a celebration to mark the end of Yule called Up Helly Aa. Here in the Shetland Islands, off the northern coast of Britain, the cultural influence of the Vikings is still felt. And when the Yule season comes to a close, many Shetlanders dress up like Vikings—it’s a tradition called ‘guising,’ short for ‘disguise.’ In their Viking costumes, they march the streets of Lerwick singing songs and delivering short comedic performances. Ultimately, a torchlight procession ends with the marchers setting a fake Viking galley ship ablaze. The name ‘Up Helly Aa’ is roughly translated as Up Holy All, an invitation for all to rise and join in the holiday revelry.