By Erika Owen
Updated: January 24, 2017
AFP/Getty Images

Travelers are hustling to Poland in search of gold—specifically a Nazi train filled with treasure that's thought to live in an undiscovered tunnel constructed by the Nazis. Throughout World War II, a series of subterranean tunnels were constructed underneath the Ksiaz Castle, a medieval building in Walbrzych that was supposed to eventually serve as Adolf Hitler's headquarters. It is thought—there is no proof—that a train filled with gold still lives underneath the castle today, untouched since the tunnel entrances were destroyed when it became clear the war was coming to an end. The search has been going on for years for a few, but it's only recently that the Polish government announced that anyone who discovers the train will have a right to 10 percent of the convoy's cargo. 

There have been close calls in the past—two locals in 2001 struck what they think was a supporting tunnel wall while digging near a local railway for the secret shaft. Another treasure seeker pointed out a raised formation in a nearby forest that shares a suspiciously similar shape to a train tunnel. Currently, there hasn't been any confirmation as to the train's existence. Nevertheless, sounds like a great reason to visit the country of one of the world's best cities.

Erika Owen is the Audience Engagement Editor at Travel + Leisure. Follow her on Twitter and Instagram at @erikaraeowen.