A map by Henricus Martellus from 1489. Image Credit: Yale University Library

The mistake that took Christopher Columbus to the Caribbean in 1492, rather than the east Asian destination he was hoping for, might have been a product of the map above.

The 15th century map by the German cartographer Henricus Martellus is thought to be the best map we have illustrating Columbus’ perception of world geography. It’s housed at Yale University’s Beinecke Rare Book and Manuscript Library, where an imaging team has been analyzing it to read writing that has faded into invisibility over the centuries. They photographed the area rug-sized map under 12 different light frequencies to reveal the more than 500-year-old text.

Smithsonian magazine created this nifty infographic of some of the information hidden inside. 

The 6-foot-tall map is believed to be from around 1491. It quotes an encyclopedia published in the same year, and its depiction of world geography is consistent with our understanding of where Columbus thought he was going. On the eastern portion of the map, it shows Japan—Columbus' intended destination during his initial 1491 voyage—as being just across the ocean from Europe and Africa. Of that land mass, the map says: “This island is 1000 miles from the continent of the province of Mangi [a term for southern China]; the people have their own language and the circumference of the island is [illegible] miles.”

On the bright side, they managed to get three of the seven continents right. 

[h/t: Smithsonian]