Location from Solo Leveling by Chugong
An S-Rank gate on Jeju Island that spawned the Ant King — Korea's greatest crisis, requiring an international raid that nearly ended in total failure.
The Jeju Island Gate was an S-Rank gate that opened on South Korea's Jeju Island and spawned an army of giant magic ants led by the Ant King, the most powerful magical beast Korea had ever faced. Two previous Korean raid attempts failed with massive casualties. A third attempt was organized as an international effort, bringing in Japanese S-Rank hunters alongside Korea's best. Even this combined force was being overwhelmed until Jinwoo arrived with his shadow army and killed the Ant King. The Jeju Island raid is a turning point — it's where the world first saw what Jinwoo could really do.
Also known as: Jeju Island Gate, Jeju Island, The Jeju Raid, Jeju