The rare 14th-century portolan chart is worth $7.5 million. Robert Gauthier / Los Angeles Times / Getty Images Last fall, Christie’s auctioned off a “highly unusual” nautical map as part of an estate ...

Add Yahoo as a preferred source to see more of our stories on Google. La Jolla map dealer Alex Clausen came across this rare 14th century nautical chart at an estate sale for Ann and Gordon Getty.

In the last third of the 16th century, the Spanish crown set in motion a project to obtain a complete map of the New World. The method thought up for this was to use surveys, known as Relaciones ...

One drawback is that nautical charts are often pretty big, perhaps three feet across and two-and-a-half feet from top to bottom. On big ships, navigators use a large chart table to view charts ...

Alex Clausen is a map dealer. And although that designation may not, at first read, exude adventure and romance, Clausen really is a modern-day treasure hunter. He doesn’t sail the seas in search of ...