One of the best ways to get your bearings is with an easy coastal walk, such as the Gwaneum Island hiking trail.
The one-hour walk takes travelers over a bright blue pedestrian suspension bridge to an outlying island called Gwaneumdo.
The short yet steep hike takes you through ancient forests and silvery grasslands, as you make your way toward viewing platforms framing the sea.
"Gwaneumdo offers one of most beautiful walks in Ulleungdo. It is covered with reed forest," says Jang. "There are three popular observatory around the hike, including views of Bamboo Island and Three Fairy Rocks."
For more experienced hikers, a trek up to Seonginbong -- the island's highest peak at 3,228 feet -- promises a huge payoff on a clear day.
Of the many ways to reach Seonginbong, Jang recommends a walk along the Nari Basin Forest Trail, part of the Nari Basin Geopark.
Located in the center of the island, the basin was created after a volcano eruption millions of years ago. Today, it's best known for its extensive collection of indigenous flora, Mountain Spirit Mineral Spring, and rare mountain vegetables.
"Surrounded by layers of mountains, the Nari Basin is the only flatland in Ulleungdo where many wild mountain vegetables grow," says Jang.
"Within the geopark, you can also admire the cloud fall, layers of clouds which look like waterfall, and fantastic views in the autumn as the leaves change color."
Then there's Bongnaepokpo Falls, where three tiers of water tumble from a height of 25 meters. The vast majority of hotels and restaurants around the area source their drinking water from this pristine waterfall.
In the surrounded redwood forest, hikers can cool off in front of a "natural air conditioner" formed by holes in the boulders.
Stand in front of the cave-like crevice and you'll feel a steady blast of cool subterranean air, which maintains a consistent temperature of 4 degrees Celsius all year.
For the best views on Ulleungdo, Jang suggests a trip to the Seokpo Observatory -- the only spot on the island where you can enjoy both sunset and sunrise.
On the water
Ulleungdo is a popular destination for scuba diving, kayaking, fishing and swimming.
courtesy Kate Springer
The island is home to clear water that's teeming with marine life, so it's no surprise that Ulleungdo has become a hot spot for scuba diving, kayaking, fishing, and swimming.
Before diving in, we'd recommend taking a scenic boat or fishing tour around the island. From May till November, there are several three-hour tours that depart from Dodong, the main ferry port.
The itineraries typically zig through dramatic rock formations, stop by an old pirate's cave, and afford excellent views of the landscape along the way.
A few tours also provide opportunities to catch fresh red sea bream, butter fish, mackerel and rockfish with experienced local fishermen.
With its clear waters and abundant marine life, the island has become the go-to destination in South Korea for serious divers.
"Ulleungdo attracts divers because of far visibility, large fish and dynamic topography," says Jang. "Throughout the year, a 20- to 30-meter range of visibility is guaranteed, and you can often see as far as 50 meters."
Jang suggests visiting between August and October to experience the best of underwater scenery. "Thanks to the Kuroshio current, you can see tropical fish swimming north with the current."
Kayaking is another way for adventurous travelers to freely explore the waters of Ulleungdo.
Particularly in the waters around Gwaneumdo, on the northeastern coast, kayakers will be surrounded by dramatic cliffs, stoney beaches, and fascinating rock formations such as Elephant Rock.