The gaping flame-filled crater has been this way since 1971, when Soviet geologists tapped into a cavern of natural gas and decided to burn it off so it wouldn’t poison anyone. They thought it would take a few days. Four decades later, locals refer to this pit as the Door to Hell.
In a remote part of the mountains of China’s Hunan province lie over 3,000 spires of Cretaceous sandstone covered with clinging pine trees. The United Nations named Wulingyuan National Park a UNESCO World Heritage Site in 1992, calling it one of the most remarkable geomorphological spectacles that exists on our planet.