Jeju Island was formed 1.2 million years ago as a result of powerful volcanic activity. The center of the island, or better to say its heart - an extinct volcano, Mount Hull (1950 m), now the highest point in South Korea. In addition to the main volcano, around the island scattered about 350 smaller craters. It's terrible to imagine how all this was boiling during the formation of the island.

Besides volcanoes and craters on the island there are other interesting evidences of those hot days, but they are hidden underground. These are the so-called "lava pipes" or "lava caves", which were formed at the moment of the movement of the red-hot lava flows from the centers of the eruption to the periphery. Some of Jeju's lava pipes are among the largest in the world. For example, the cave of Manchangul stretched more than 13 kilometers. At present, a trail of about a kilometer long in the pedestrian is highlighted and turned into an interesting walking route.

Here you can visually see how the lava flows moved, bypassing hard rocks and setting a tortuous route. The upper part of the stream cooled down under the influence of air, while in the full steam the lava flowed at full speed. So formed the picturesque upper vaults. The walls were clearly reflected in the strips as in the subway tunnel, showing how the depth of the stream changed as the eruption ended. When all the lava emerged, the remnants froze, forming a corrugated floor. For lovers to stumble, it is better to refuse to go here.

Despite the fact that the streams of red-hot lava moved here quite a while and probably will not soon flow again, intuitively you feel some kind of alarm from understanding what trap you fell into. If there is a sudden outburst, there will be no chance of escape!

The cave retains a constant temperature of about 15 degrees and high humidity. So in winter it is possible to warm up and hide from the wind, and in summer to take a break from the heat. Since Manzhangul is the largest and most famous of the Jeju lava caves, there are more who want to see it more than anywhere, which makes it difficult to shoot at long exposures.

At different times, the caves served as a secret shelter from the invaders , and also helped everyone who for some reason wanted to be alone. And, of course, there are a lot of legends about deep-living dragons, stolen beauties and brave warriors, which enriched local folklore.

In 2007, Jeju Island was fully included in the list of Unesco objects, as a unique whole natural system: "Jeju volcanic island with its lava tunnels."