South Korea’s southern island of Jeju beckons with trek on a hidden trail through Geomunoreum, a UNESCO world natural heritage site.

Geomunoreum International Trekking, an event taking place Thursday through Monday, will be held around Geomunoreum, a volcanic cone northeast of Hallasan, South Korea’s tallest mountain.

The five-day event offers a rare opportunity to explore Yongam-gil, a restricted zone.

Yongam-gil, meaning “lava path” in Korean, is a 6-kilometer walking path formed by the island’s basalt lava flows.

The walking tour, which starts from Jeju’s World Natural Heritage Center and ends at a local cafe, Butchers, allows hikers a chance to enjoy a close-up view of Baengdwigul, one of three naturally formed caves at Geomunoreum. Entry to the cave, however, is not allowed.

Free shuttle buses will be available for visitors to travel back to the World Natural Heritage Center.

Yongam-gil requires about 3 1/2 hours to complete, according to Geomunoreum International Trekking Committee, the event organizer. The trail will be closed off after the five-day event.

Meanwhile, Taegeuk-gil -- another walking tour under Geomunoreum International Trekking -- takes hikers via three different routes to the oreum’s crater, peak and ridge.

It is expected to take 3 1/2 hours to walk the 10-kilometer Taegeuk-gil.

Passes to tour Geomunoreum are distributed at the Tourist Information Center in World Natural Heritage Center. No reservations are needed.

Admission is free during the Geomunoreum International Trekking period.