Watching these freediving elderly women made the hair on my arms stand up

Seongeup, on the island’s south-eastern side, is a ­living heritage village of thatched stone houses, shrines and low basalt walls dating back more than six centuries. We pass between two dol hareubang statues, hand-carved volcanic-stone “grandfathers” traditionally regarded as guardians, and wind our way down an olle, one of the narrow lanes connecting to the main road. “There’s a saying on Jeju,” says my guide: “‘Every road begins with an olle and leads to the world’.” The name now belongs to Jeju’s 437-kilometre Olle Trail, whose 27 routes lace the island’s coast and countryside.

Inside a small Seongeup shop, I run my hands over stiff, rust-coloured galot, workwear Jeju islanders have dyed with persimmon juice for centuries, the ­tannins helping protect the cloth from sweat and dirt. Nearby, signs advertise natural-dyeing and ceramics workshops, and I begin mentally designing a return trip, when I’ll stay in a traditional house, walk the Olle Trail, throw a few pots and dye my own cloth.

For now, though, I’m due in the small village of Sehwa. There I meet 34-year-old Ta-eum Kim, part of a new generation of young women choosing the haenyeo life. She shows me around the Haenyeo Museum, once a gathering place for haenyeo protesting exploitative seafood prices under Japanese colonial rule in the 1930s, before we walk to the bay where she dives. “We don’t catch everything we see,” says Kim. Unlike industrial fishing that can scrape the ocean floor, haenyeo gather their catch by hand, leaving undersized shellfish to grow. “We take only what we need to earn a living so that the marine life in this ecosystem can continue to live as well.”

Kim’s words are still with me on my final morning on Jeju. So, too, is the sense that, for all South Korea’s associations with the hyper-modern, this island has something important to say about how we might live now: take only what you need. Work with, rather than against, nature.

With my back to the wind, I walk the coast from Hamdeok, the popular beach town in the island’s north-east. I pass a dol hareubang standing sentinel beside the path and walk on, the sea stretching blue and empty beside me.

The writer travelled to South Korea courtesy of National Geographic Journeys with G Adventures.