The western edge of the known world is a topic that has come to haunt us. Keen to ensure a propitious start when hidden europe was launched in early 2005, we journeyed to Cape Finisterre on the Galician coast of northwest Spain, and there, anxious to escape the worst assaults of a howling gale, we huddled in the lee of the lighthouse at the very end of the earth, and wrote the editorial for the first ever issue of the magazine. Then last year, we reported from the westernmost extremity of the Azorean archipelago, where the islands of Flores and Corvo stake out their claim to be the end of Europe - and in times past the edge of the known world. And now, as it happens, we can reveal another place that, for generations of European cartographers, represented the end meridian - the line beyond which there was nothing but sea.
When Columbus first crossed the Atlantic, the last trace of European land which he and his seafaring crew saw, before sailing west to the Bahamas, was the island we know today as El Hierro, the westernmost and the smallest of the seven principal islands in the Canaries group. Back in 1492, El Hierro was shown on most maps as Ferro - a name it had inherited from the geographers of the classical world, to whom this isolated outpost in the Atlantic represented the furthest edge of the known world.
Even in the ancient world, map-makers were alert to the importance of identifying a prime meridian: that is, a north-south line of longitude that might conveniently serve as a baseline for referencing location.