Jeju, a volcano ringed by black rock

Jeju is a shield volcano in the sea off Korea's south coast, and everything about the island comes from that: black basalt walls dividing the tangerine groves, lava tubes under the fields, and hundreds of small parasitic cones — oreum — rising out of the pasture. At the centre stands Hallasan, at 1,947 metres South Korea's highest mountain, with a crater lake at the summit and day-hike routes, open when conditions allow, that climb through dwarf bamboo and, in May, blooming azaleas.

The coast is the other half. Seongsan Ilchulbong, the Sunrise Peak, is a tuff cone that erupted out of the water and now stands as a green bowl above the cliffs — the classic dawn climb. Along the south shore, Jusangjeolli breaks into hexagonal columns of cooled lava that the waves hit head-on, and Cheonjiyeon and Jeongbang waterfalls drop close to the sea at Seogwipo. Underground, Manjanggul lets you walk a kilometre into one of the world's finest lava tubes.

Jeju's culture is just as distinct. The haenyeo, the island's women free-divers, still work the shallows for abalone, conch and sea urchin without air tanks, many of them well past seventy, and their guild houses are part of the coastal landscape. Squat basalt dol hareubang grandfather statues guard the village entrances.

Walk some of the Olle Trail, 27 waymarked routes stitched around the whole shoreline; eat grilled black pork, abalone porridge and hallabong tangerines; and in spring cross fields of yellow canola. Jeju is the softest week in any South Korea itinerary.