Chungju Hwalok Cave (충주 활옥동굴)

Developed in 1922 during the Japanese Forced Occupation, this is the only talc mine in Korea and is the largest in the East, with a recorded length of 57km, an unofficial length of 87km, and an underground vertical x_height of 711m. A 2.5km-long stretch of the cave has been developed into a tourist site, filled with light sculptures, performance venues, and health therapy zones. LED, neon, and a variety of natural lights create a mysterious atmosphere, and since the temperature stays between 11 and 15 degrees year-round, it's even more popular in summer. There is also a kayaking experience that allows visitors to see inside the cave by kayaking in a lake created by mineral water.<br> Note that the temperature inside the cave averages between 11 and 15 degrees Celsius, which is warm in the winter but cold in the summer, so you'll want to bring a long-sleeved jacket.<br>