In Japan,关键字1 the number nine is considered unlucky because the word for nine is pronounced similarly to the word for suffering. In China, there’s a similar superstition around the number four—its pronunciation is similar to the Chinese word for death. In Afghanistan, 39 is considered taboo, in part because it sounds like the words for “dead cow” when said aloud. But of all the numbers surrounded by superstition, there’s one that comes up especially often: 13.

From Norse mythology to the Mayan calendar, the number 13 has been associated with misfortune, danger, and death. There’s even a word to describe the fear of this ill-fated integer: triskaidekaphobia. It’s considered especially unlucky when the 13th day of the month falls on a Friday. That’s a more recent superstition, only dating back to the 19th century. (In Greece and many Spanish-speaking countries, it’s actually Tuesday the 13th that’s considered unlucky.)

Like numbers, days of the week, gestures, or even animals, places are often the subject of superstition. Many won’t speak the name of a particular town in Italy out of fear that it will bring misfortune. In Thailand, any visitor who dares to take a pebble off the beaches of Ko Hin-Ngam is said to be forever cursed. These associations may simply be tall tales, but here are a few unlucky places to avoid this Friday the 13th, just to be safe.