The hook
A volcanic island 120 km out in the East Sea with almost no flat ground — steep enough that the coastal road had to be drilled through the cliffs — and a visitor list that is mostly older Koreans and almost no foreigners at all.
01Why it's worth it
Ulleungdo is what Jeju is not. Both are volcanic islands; Jeju has an international airport, a million residents' worth of infrastructure and a permanent place on every Korea itinerary. Ulleungdo has a ferry, about 9,000 people, and terrain so vertical that villages sit in the few creases where a village will fit. The interior rises to Seonginbong at 984 m through dense forest, and the coastal loop road spends much of its length in tunnels because there was nowhere else to put it.
The island is Korea's squid capital, and the working economy is visible in a way it usually isn't in a place people visit — fishing boats, drying racks, guesthouses full of fishermen rather than travellers. It is also the jumping-off point for Dokdo, the disputed islets 87 km further east, and a large share of domestic visitors come specifically to stand on them. Whether that interests you is a matter of taste; several Korean commenters are frank that it does not interest them either, and they rate the island on its own terms regardless.
Nari Basin, the flat crater floor in the island's north, is the one place where the ground relents, and it's where the traditional shingle-roofed houses and the island's wild vegetables come from. The coastal walkways cut into the sea cliffs are the other thing people remember.
02How to experience it
Ferries run from Mukho, Gangneung and Pohang; the fast boats are shorter and the slow ones more reliable. Give it three days minimum, and build slack into your return — see below. Hire a car or use the island bus for the loop road, climb Seonginbong, and walk the cliff paths. Come in late spring or early autumn.
The honest note
The ferry is the whole risk. One traveller's account of being stranded is worth reading before you book: they went out in September 2015 while living in Korea, found the trip out "smooth and uneventful," and then "my attempt to return to the mainland peninsula was a different story" — with a long weekend closing in on the mainland. Rough seas cancel sailings, and the island does not care about your onward flight. Do not schedule Ulleungdo against a hard departure date.
It is expensive in season and has a reputation for it. A Korea-travel regular recommending the island still attaches the caveat plainly: it "has a bad reputation for not being able to eat alone and ripping off customers in the peak season." The solo-dining problem is real across rural Korea — many restaurants serve minimum two portions — and it bites hardest somewhere with few alternatives.
It is a lonely trip if you want company. A solo traveller describing Korea outside the big cities said that "travelling around Korea outside of Seoul and Busan is a lonely affair," and gave this island as the example: "Ulleungdo for example, I met a local girl who grew up there and it was great, but my guesthouse was full of old fishermen." That is either the appeal or the problem, depending on why you came.
From the locals
The strongest endorsement is also the bluntest, from a list of things to do with a month in the country: "If you're feeling extra adventurous, go to Ulleungdo! Best place in Korea."
The most useful framing comes from someone answering Korea-travel questions, who puts it directly against the island everyone already knows: "Much smaller island than Jeju and also harder to get to but (IMO) this is what makes it worth it."
And it opens a Korean-travel "hidden gems" list explicitly built around what foreigners miss — the writer's stated criterion was places "not visited by foreigners while others are not visited by foreigners OR Koreans," and Ulleungdo was number one: "Usually visited a lot by OLDER Koreans, but younger Koreans and foreigners? Forget about it."
A family who spent 23 days driving the country and included it gave the shortest verdict: "It was amazing and exhausting."