Seongsan Ilchulbong, a tuff cone on Jeju Island, South Korea

© Quynh Anh Nguyen/Getty Image

A 'tuff'-tastic crater. Jeju Island, South Korea

The South Korean island of Jeju is full of wonders. If you don't have a chance to visit its volcanic landscape, ancient stone statues, waterfalls, and rocky coastline, you can dive into the island's fascinating chronicles from the comfort of your computer. The star of today's image, Seongsan Ilchulbong (Sunrise Peak), is the island's rare tuff cone formation, created by an underwater volcanic eruption about 5,000 years ago. Tuff cones are also called ash cones, referring to the accumulated ash settling in a cone formation after the lava's forceful explosion. Seongsan Ilchulbong was added to the UNESCO World Natural Heritage List in 2007.