Why there are sea monsters lurking in early world maps?

That’s the playful moniker Dory Klein of the Boston Public Library uses for the creatures found in centuries old maps. She’s an education and outreach assistant at the library’s Norman B. Leventhal Map Center.“In the Medieval and Renaissance period in Europe, people didn’t really know what was out there,” Klein says. “So your corpus of knowledge came from folklore and the Bible. And so in that world, monsters could very well be real and they were just part of this supernatural landscape. Background to the popular twitter hastag #MapMonsterMonday –  http://short.pri.org/QizxeAC