Water at the summit? Meet Mulyeongari Oreum, a wetland inside a crater
Talk about oreum in Jeju long enough, and you'll eventually hear a phrase that stands apart from the rest: an 'oreum with water.' Most oreum are said to have craters that stay dry land even when a crater is present, but a handful of oreum are said to actually hold water inside their craters, forming a wetland. Mulyeongari Oreum, the one I want to introduce today, is said to be exactly that kind of oreum — registered as a wetland under the Ramsar Convention, the international treaty formed to protect wetlands. Hearing that an entire oreum has become a protected wetland might make some people tilt their heads and wonder, 'what wetland could possibly be on an oreum?' So today I wanted to unpack this unusual oreum's story in an easy, relaxed way.
Water pooling inside an oreum — what does that even mean?
Most oreum in Jeju are said to have craters formed by volcanic activity. But it turns out these craters don't all stay dry. Jeju's ground is said to be rich in basalt from volcanic activity, which lets rainwater seep down quickly, so landforms that hold surface water for long aren't common to begin with. Mulyeongari Oreum, though, is said to have slightly different geological conditions at the bottom of its crater compared to other oreum, so rainwater doesn't drain away easily and instead stays pooled inside the crater. Wetland-specific plants are then said to have taken root around that standing water, forming a small wetland ecosystem right at the oreum's summit.
What's interesting is that this wetland doesn't look the same all year round. During the rainy season, water is said to rise and the wetland spreads out wide; during drier stretches, the water recedes and the wetland's area shrinks along with it. So the scenery you encounter can shift a fair amount depending on when you visit — and I find that part especially charming. The idea that the same oreum shows a different face depending on the season, or on that year's rainfall, makes it feel almost like a living creature.
A rare kind of oreum, recognized as wetland under the Ramsar Convention
The Ramsar Convention is said to be an international treaty that a number of countries joined together to protect ecologically important wetlands, including waterbird habitats. When people hear 'wetland,' they usually picture a river estuary, a tidal flat, or a low-lying marsh — so it's said to be a fairly unusual case that Mulyeongari Oreum's wetland sits near the summit of an oreum that's fairly high in elevation. Exactly when it was registered as a Ramsar wetland seems to be recorded slightly differently across sources, so I'll be careful not to pin down one specific year here — but what does come up consistently is that it's internationally recognized as a wetland worth protecting.
The fact that water collects at the summit of a mountain seems, in itself, to show just how quietly this oreum has held onto its own share of water for so long.
— 🍊 GYULIBecause Jeju is a volcanic island, rainwater is said to seep into the ground quickly, so places where surface water lingers for long aren't common to begin with. Maybe that's why wetland oreum like Mulyeongari are sometimes mentioned as one of the few habitats where dragonflies and other wetland-dependent insects, along with aquatic plants, are able to settle in. To people, it comes across as a mysterious sight, but for the small creatures that depend on the wetland, it's said to be an irreplaceable, precious home. Thinking about it that way changes how I look at a single oreum, even just a little.
A special experience: meeting a wetland at the summit
People who visit Mulyeongari Oreum say that as they climb along the ridge and reach the summit, they're met with an unexpected wetland view. It's said to be a sight you don't get at most other oreum, so people seeing it for the first time are often said to be genuinely surprised. That said, since this is an ecologically protected wetland, visitors are generally advised to stay on the designated trail rather than stepping into the wetland itself. It's understandable to want a closer look, but keeping a respectful distance and taking it in with just your eyes is said to be how this small ecosystem gets to stay protected for longer.
The more I learn about this oreum, the more I find myself thinking that Jeju really does have many different faces. Some oreum are known for their soft ridgelines, and others, like this one, hold a wetland inside them. They might all look like similar green hills from the outside, but look closer at each one and they seem to carry their own distinct story — which I find genuinely fascinating. Next time you come across an oreum in Jeju, I hope you'll look at it with a bit of curiosity about what secret it might be holding.
GYULI's Tip · Since the wetland sits at the oreum's summit, a trail and steps are often said to be built alongside it. To help protect the wetland ecosystem, it's best to stay on the marked path.