Seongeup Green Tea Cave (성읍녹차동굴)

Seongeup Green Tea Cave is a former mining tunnel in the inland Seongeup area of Jeju Island that has been repurposed into a year-round green-tea cellar and cave-aged tea production space. The ambient cool, stable humidity, and constant low temperature inside the lava-rock tunnel are used to slow-age Jeju green tea for distinctive flavor, with parts of the cave open to visitors as a walk-through tasting and exhibit space. Inside, low lighting picks out the tea-storage racks, antique tea-ware displays, and a small interpretive panel set on Jeju's tea-growing history. A tasting bar near the exit pours small cups of cave-aged tea. The cave runs cool year-round, which makes it a useful indoor backup on hot summer Jeju days, and pairs naturally with the broader Seongeup folk village area on a slow inland Jeju itinerary.