Thule & Ultima Thule
"The classical antiquity frontier marking the northernmost boundary of the habitable world"
Reported by the Greek explorer Pytheas of Massalia c. 325 BCE, Thule was described as a land of midnight sun six days' sail north of Britain, where water, earth, and air merged into a gelatinous substance resembling a 'sea-lung' (*pleumon*).
Cartographic Origin Story
Pytheas’s lost account *On the Ocean* cited by Strabo, Pliny the Elder, and Ptolemy, who fixed Thule as the northern limit of his *Geographia* coordinate system (63°N).
Served for over two millennia as the conceptual edge of cartographic epistemological limits (*Hic sunt leones / Ultima Thule*).
Scientific Disproof or Geological Fate
Gradually identified with Iceland, Norway, or the Shetland Islands as maritime exploration pushed the borders of the known world northward.