Ultima Thule in medieval geographies may also denote any distant place located beyond the "borders of the known world."
Is this small island Ultima Thule - the mythical, farthest north piece of land? Before satellite imaging, google earth, GPS positioning and so on, our knowledge still knew some limits, and the mythical northerly land of Ultima Thule saw various claims to it's location, the proposed sites progressively moving further north as exploration and discovery advanced. Theoretically at least, we should be able to view from the sky where this most northerly piece of land lies, and allow the mystery of Ultima Thule to be solved. Thankfully, it's not that easy. Scientists and explorers (and the odd eccentric) have continued to try to locate the spot, and arguments and splits between opposing groups has meant that there is still continuing debate as to where the land might be, each faction claiming their own success in locating Ultima Thule.
The problem comes from what one defines as an island. A few years back, a group reached a bed of shingle and rock off the north coast of Greenland, naming it Ultima Thule, but the problem with naming and fixing any location so far north in the arctic sea ice, is that such land spits, shingle deposits, sand banks, etc, are mutable. As the ice pack ebbs and flows, land appears and disappears seasonally, often transformed along the way. With global warming, new land is constantly being discovered, only to be lost the next year - Phantom Islands, as it were. At the time of photographing, the image above was considered to be the limits of northern land, but even this has since been disproved. Looking for this evidence online, I was initially frustrated that even with modern technology, we still couldn't locate this place, but now that I think more, I'm relieved that at least one of the last mysteries of the earth's landforms remains elusive. As soon as the furthest posssible place in the world becomes a place, the unknown becomes known and leadenly fixed, and the space of dreams and imagination dies just a little bit more. And while the romance of going to the farthest place has sparked the imagination of a few, it doesn't quite have the draw of an Everest, of summiting an unclimbed peak or any one of the many permutations that polar and mountain explorers have challenged themselves to (first woman, youngest, oldest, fastest, to reach both poles, 7 summitts, the 14 peaks above 8000m etc - the permutations of being the 'first' seem endless).
There's a distinct lack of glamour in the actual trip, and the cost of achieving this is so prohibitive that it remains unlikely that many will seek out the challenge, a challenge that looks equally likely to be disproved almost as soon as "success" is achieved.