The ruins of a 15th-century church once home to priests who prayed for a single family's salvation.

The poems Nathaniel Hawthorne and his wife Sophia etched into its windows are still visible today.

The oldest standing Byzantine church in Athens is tucked within a monastery in the middle of an upscale shopping district.

People leave coins atop an unusual grave marker in one of Scotland's oldest burial grounds.

A subterranean relic of the Spanish Civil War hides below this picturesque park.

Sound travels strangely in this underground whispering gallery.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

The first thermometer made with the almost-universal temperature scale is backwards.

Archaeologists are still unraveling the secrets of the brutal massacre that wiped out this ancient fort.

An otherworldly, fossil-rich cobble beach holds Viking graves, cairns, and other remains.

The second-largest collection of runic calendar staffs in Sweden.

The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

The world's largest underground iron ore mine.

This enigmatic artifact is a rare depiction of an ancient Iberian noblewoman.

A grave marker depicting a body snatching tableau on a 19th-century tombstone.

A 1:42 scale model of the world's second largest lensed telescope.

The beloved bard's garb is proudly displayed within a Freemason's hall.

This gem from the industrial age helps visitors and residents alike traverse hilly Stockholm.

This Soviet statue is based on a piece of propaganda that's been elevated to national myth.

The world’s first museum dedicated to the history of childhood opened in Edinburgh in 1955.

The world's largest frame offers spectacular views of the city's past and present.

Dine amidst exotic plants at this former royal greenhouse.

This allegedly haunted 16th-century tower house-turned-museum exhibits thousands of spectacular objects.

Hidden on two floors of downtown building, the library has an incredible deal on rent.