The Giant's Causeway in Ireland is perhaps the most well-known example of seaside columnar basalt cliffs...and here on this green volcanic island on the other side of the world is a less well-known locale where you can find this geologic phenomenon. (Hint: it's subtropical and regionally famous for its tangerines and diving women.)
Early European maps referred to this as "Quelpart" island. Dutch sailor Hendrick Hamel was shipwrecked here in the 1600's and wrote one of the first European accounts of this place, which served, for a time, as a penal colony for what came to be called "The Hermit Kingdom."
Have you guessed where "Quelpart" is yet?
These are the Jusangjeolli cliffs, (pronounce approximately like joo-sahng-jolly), a dramatic 2-km-long stretch of the southern coastline of Jeju-do ("-do" means island), off the coast of South Korea, where the Yellow Sea becomes the East China Sea.
Last year, the New7Wonders Foundation based in Zurich, Switzerland named this island one of the 'new 7 wonders of nature,' along with places such as Iguazú Falls and Halong Bay...
Development is happening quickly, but Jeju island is still a bit off the beaten path for most Westerners in Asia--if you're willing to rough it a bit, rub shoulders with Chinese, Japanese, and Indonesian tourists, and try some so-fresh-it's-scary seafood, you'll enjoy your island-time here.