Hallasan is a massive shield volcano that effectively defines the identity of Jeju Island.

Countries & Cities · Published 30 September 2026 Swipe more like this →

In short: Rising 1,947 meters above sea level, Hallasan is the highest point in South Korea. This shield volcano is so central to the local landscape that a traditional saying claims the island and the mountain are one and the same. Its slopes host unique ecosystems, ancient temples, and hundreds of parasitic cones.

Hallasan is a massive shield volcano that forms the bulk of Jeju Island. Constructed on the continental shelf during the Pliocene epoch, the mountain reaches a peak of 1,950 meters, though its official summit is 1,947 meters. The volcano is topped by a large crater over 400 meters in diameter, which contains Baengnokdam, a crater lake formed by the collapse of the ridge. While geological evidence suggests the last eruption occurred at least 2,000 years ago, historical records from Goryeosa mention an eruption in 1007 CE, leading to its classification as an active volcano.

The mountain's geography creates a unique vertical climate gradient, allowing subtropical and alpine plants to coexist. This isolation has fostered high biodiversity, including 50 unique plant species and 121 bird species. The mountain is also home to 4,300 insect species and 254 types of spiders. Mammal populations, however, have struggled due to isolation and human activity; while roe deer populations have recovered through protection policies, other species like weasels and badgers are in decline, and tigers have long been extinct.

Beyond its natural significance, Hallasan holds deep cultural importance. It is home to Gwaneumsa, the island's oldest Buddhist temple, originally built between 1046 and 1083. Destroyed in 1702, it remained closed for two centuries before being rebuilt in 1908. Today, the mountain is a protected national park featuring five hiking trails, though only two—the Gwaneumsa and Seongpanak trails—reach the summit. The others, such as the Donnaeko trail, are partially closed to facilitate the restoration and protection of the mountain's fragile vegetation.

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