Hidden-Treasure Facts

Karl Kissner was cleaning out his late grandfather's attic in Defiance, Ohio when he found a dusty box. Inside were roughly 700 baseball cards from 1910 - including 16 Ty Cobbs and a Honus Wagner - in near-perfect condition, untouched for a century. The collection was valued at $3 million.

A Virginia woman bought a napkin-sized landscape at a West Virginia flea market in 2009 for $7. She wanted the plastic cow and the doll in the same box. Two years later she learned the little painting was a genuine Renoir worth $100,000. Then the FBI showed up. The museum had reported it missing in 1951.

Michael Sparks paid $2.48 at a Nashville thrift store for a yellowed scroll he thought was an engraving. It was one of only 200 official copies of the Declaration of Independence, printed for John Quincy Adams in 1823. The previous owner had donated it by mistake after his wife cleared out the garage. It sold at auction for $477,650.

Luigi Lo Rosso, a junk dealer from Capri, found a rolled-up canvas in a villa cellar in 1962 and hung it in his family’s living room. His wife called it “horrible.” Experts now believe it may be a genuine Picasso - a portrait of Dora Maar created between 1930 and 1936 - and have valued it at up to €6 million.