Olaus Magnus' Carta Marina
The map has long been seen as gorgeously ornate, but technically crude, lacking in the sophistication that characterizes modern cartography. However, researchers four years ago found that the fanciful swirls and whorls drawn on the map of the seas east of Iceland are potentially much more than just bored artistic license: they correspond with astounding accuracy to thermal satellite imagery of the Iceland-Faroes Front, where the Gulf Stream meets the colder Arctic waters, creating huge eddies - bodies of water up to a hundred kilometers in diameter that spiral lazily as the waters of different temperatures interact.
What I found most interesting was that though the map was reissued in 1572, the new map meticulously reproduced the original Carta Marina down to the last detail except for those swirls and whorls. Thirty years on, it seems that the mapmakers had simply forgotten or not understood the function of the whorls in conveying useful navigational information. These symbols, once laden with content and meaning, faded into mere aesthetics - the fate, I thought then, of careless religious gesture, like prayers uttered without faith, or traditions celebrated without understanding or remembrance. How much of the past is like that to us? - dead or unrecoverable contexts, lost meanings, inexplicable deeds... Well, at least in the absence of meaning, the Carta Marina is still beautiful (best viewed large, scrolling reverentially). One could hardly say that for some history, especially the parts that seem the most devoid of meaning of all.