Jeju Volcanic Island and Lava Tubes - Credit: Wikimedia Commons
The Jeju Volcanic Island and Lava Tubes is a World Heritage Site in South Korea. It was inscribed as one of the UNESCO World Heritage Sites in 2007 because of the Geomunoreum Lava Tube System and the exhibition of diverse and accessible volcanic features which are considered to demonstrate a distinctive and valuable contribution to the understanding of global volcanism. Read more on Wikipedia
Source: en.wikipedia.org