Here there be dragons

(Latin: hic sunt dracones) means dangerous or unexplored territories, in imitation of a medieval practice of putting illustrations of dragons, sea monsters and other mythological creatures on uncharted areas of maps where potential dangers were thought to exist.

Dragons appear on a few other historical maps:

• The T-O Psalter world map (c. 1250 AD) has dragons, as symbols of sin, in a lower "frame" below the world, balancing Jesus and angels on the top, but the dragons do not appear on the map proper.

• The Borgia map (c. 1430), in the Vatican Library, states, over a dragon-like figure in Asia (in the upper left quadrant of the map), "Hic etiam homines magna cornua habentes longitudine quatuor pedum, et sunt etiam serpentes tante magnitudinis, ut unum bovem comedant integrum". ("Here there are even men who have large four-foot horns, and there are even serpents so large that they could eat an ox whole.")

• The Fra Mauro Map (c. 1450) shows the "Island of Dragons" (Italian: Isola de' dragoni), an imaginary island in the Atlantic Ocean.^[6] In an inscription near Herat in modern-day Afghanistan, Fra Mauro says that in the mountains nearby "there are a number of dragons, in whose forehead is a stone that cures many infirmities", and describes the locals' way of hunting those dragons to get the stones. This is thought to be based on Albertus Magnus's treatise De mineralibus.^[7] In an inscription elsewhere on the map, the cartographer expresses his scepticism regarding "serpents, dragons and basilisks" mentioned by "some historiographers".^[8]

• A 19th-century Japanese map, the Jishin-no-ben, in the shape of ouroboros, depicts a dragon associated with causing earthquakes.