In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

The Polish capital has had a deep connection to its guardian mermaid for almost a millennium now.

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Real bones which are said to have belonged to a Polish dragon.

An underground city of salt.

The bullet-riddled wall from the St. Valentine's Day Massacre, bloodstains enhanced for your viewing pleasure.

After a water tower painting was accused of being an ad, a simple fix was made that gave the city a motto.

Amazing taxidermy dioramas from the 1960s in a cement building meant to look like an ice cave.

A 70,000-square-foot institution dedicated to a very literal, creationist perspective on the Book of Genesis.

Moonbows over Kentucky.

The world's longest known cave system.

The longest navigable underground river in the United States is home to countless blind and albino animals.

The farm where one of America's greatest leaders was raised is now a well-appointed landmark.

A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

The oldest brick house in the state of Ohio.

This restaurant proudly displays bread signed by the 39th president.

It took more than 20 years and a sharp eye for one man to assemble this quirky collection.

Rare recess caves fill this unbelievably beautiful Ohio park.

The largest earthwork effigy in the world.