here be dragons

Meanings

1. A fanciful notation, commonly attributed to historical maps, held to indicate either the belief that unknown dangers exist in a certain location on the map, or that actual dragons can be found there.
2. By extension, used to indicate that which is unknown or uncertain, particularly if it seems to carry some type of risk.

Etymology

Evidence of the use of this term as a notation on actual historical maps is lacking. The only known appearance of an equivalent phrase in any language on a historical map is of Latin HC SVNT DRACONES (“here are dragons”), placed on the east coast of Asia, on the Hunt-Lenox Globe, which dates from c. 1510. The phrase is simply a variation on HIC SVNT LEONES ("here are lions"), the classical phrase used by medieval cartographers to denote unknown territories on maps.