For years I was fascinated by a place called Thule that appeared on maps of Greenland. It reminded me of Ultima Thule, the name often given by mediaeval cartographers to a territory which lay towards the edge of the map. These were the spaces where a little cartographic licence was permitted. Ultima Thule, some early maps implied, might well be populated by dragons. Generally, cartographers over the last two millennia have consistently suggested that, if it is to be found at all, then Ultima Thule is an island way up north.
This nebulous territory has however never been properly anchored and few islands on this planet have made such outlandish journeys. Ultima Thule has popped up on maps hovering off Scotland's north coast, uncertainly tethered to Estonia or generally floating around near the North Pole. Pliny the Elder, writing his Naturalis Historia in the first century AD was clear about how to get to Thule. "Six days sailing north of Britain," he wrote, even if that left some scope for getting utterly lost at sea.
Ultima Thule has been a fabulously flexible concept. Born out of cartographic exigency, it has served the interests of poets and explorers alike. Sometimes full of beasts, more often just empty desolation, Ultima Thule is inscribed on our collective consciousness as an icy fantasy that we dare not properly map. We all need such spaces in the topography of our minds, especially as the blank spaces on our maps are becoming fewer and fewer. Google Earth relentlessly plots the planet, and everywhere has been mapped, tracked and stored as a series of GPS co-ordinates.