Salina Turda is located in the Romanian region of Transylvania and is one of the world’s oldest salt mines, dating as far back as the Middle Ages. This mine is a whopping 368 feet underground and was used up until recently, when the entire area was renovated in 2009 to make way for the world’s largest salt mining museum! An amphitheater, sports arena, ferris wheel, mini golf course, and bowling lane are just some of the installations down here, making for a very unique experience. And the mine is completely devoid of any allergens and bacteria, making the micro-climate a perfect destination for anyone suffering from hay fever or asthma. Salina Turda via distractify