Seongsan Ilchulbong

Seongsan Ilchulbong, also called Sunrise Peak, is a volcano on eastern Jeju Island, in Seongsan-ri, Seogwipo, Jeju Province, South Korea. It is 182 meters high and has a volcanic crater at the top.

Considered one of South Korea's most beautiful tourist sites, it is famed for being the easternmost mountain on Jeju, and thus the best spot on the island to see the first sunrise of the year. Seongsan Ilchulbong is a UNESCO Natural World Heritage Site, as part of the item Jeju Volcanic Island and Lava Tubes.

Etymology
"Seongsan" and "Ilchulbong" are two alternate names for the mountain that only in recent years have been joined together into a single name.

"Seongsan" means "fortress mountain"; the mountain is said to resemble a Korean fortress. "Ilchulbong" means "sunrise peak". This latter name has reportedly been used since ancient times, and is derived from a belief that the mountain is one of the best places to view the sunrise on Jeju Island.

The mountain previously sometimes went by the name Cheongsan ; this name is reportedly sometimes still used by generally elderly people.

Description
In 2021, a study reported that there is a 600 m wide crater from before the formation of Seongsan Ilchulbong that now partially overlaps with the site of the mountain. Seongsan Ilchulbong was formed around 6,700 years ago, by Surtseyan-type hydrovolcanic activity upon a shallow seabed. The earliest eruption related to the peak occurred around 600 m to the east of the current crater. After the eruption stopped, magma was unable to flow through that spot, which caused magma to later emerge at the location of the peak. Over time, most of the early cones and parts of the later tuff cone were eroded by waves, leaving parts of the internal structure exposed along the cliffs. The mountain was originally disconnected from Jeju Island, but the accumulation of sediment caused the two to connect.

The mountain is considered to be geologically interesting, and is actively studied by volcanologists.

The mountain is 182 m tall and has a diameter of 600 m. It has a grassy volcanic crater in the top that is bowl-shaped and relatively flat. The crater has an area of 2.64 km2 and is around 90 m above sea level.

A 2011 study reported that there are 240 taxa of plant species on the mountain.

Tourism
The mountain is a significant tourist attraction. In 2011, it received 2.45 million visitors. In 2022, it received 1,427,941 visitors. The mountain is especially popular for watching sunrises.

Tourists can ascend the mountain using a wooden deck staircase. It reportedly takes up to 30 minutes to ascend to the top. It is open from an hour before sunrise until 8 p.m. from November to February, and until 9 p.m. from March to October. The mountain offers views of Hallasan, the island Udo, and the ocean.

Tourists can also tour the area around the mountain, and take cruises that offer views of the mountain and of Udo.

The mountain was designated a Natural Monument of South Korea on July 19, 2000. This status has reportedly aided conservation efforts on the mountain. On July 2, 2007, it was designated a UNESCO Natural World Heritage Site. In October 2010, it was named a Global Geopark Network site.

Seongsan Sunrise Festival
The Seongsan Sunrise Festival is a multi-day festival held around New Year's Day. A variety of activities and performances are held. Events like talent shows, parades, fireworks shows, and trail walking events have been attested to. In addition to popular music performances, performances like traditional gut Korean shamanic rituals are held. There is a countdown until the sunrise; fishermen reportedly light their boats and sound their whistles when it happens.

History
During the Goryeo under Mongol rule period (13th to 14th centuries), ranches for horses were established near the mountain. During the 1910–1945 Japanese colonial period and near the end of World War II, the Imperial Japanese Navy dug Tunnel Fortifications of Imperial Japan Along the Coast of Ilchulbong Peak, Jeju, where they stashed boats loaded with explosives. These boats were intended to stymie anticipated Allied landings on Jeju; the around 18 caves they dug still remain, and are now Registered Cultural Heritages of South Korea. In the 20th century, farmers reportedly grew bamboo in the crater. People raised horses and lived inside the crater before it became an environmentally protected site in the late 20th century.