Mystic Caverns and Crystal Dome are show caves located between the cities of Jasper and Harrison, in the state of Arkansas, U.S., on the Arkansas Highway 7 Scenic Byway near the defunct amusement parkDogpatch USA. Sometimes called "the twin caves" because they are within 400 feet (120 m) of each other, the two caves maintain a year-round temperature of 58 °F, contain more formations per foot than any other caves in Arkansas,[1] and are open for public tours year-round except during the January flooding season.