Mysterious heaps of stones dot these otherworldly woods.

Enormous sandstone towers loom within a Czech forest.

Visitors flock to the historic birthplace of radiobalneology for its therapeutic radium treatments.

A spiral staircase twists to the top of this unusual Czech lookout tower.

Thirty creepy ghosts now inhabit this decaying 14th-century church.

Ancient catacombs form the foundation for this Rococo orgy of a church.

A massive explosion that leveled hundreds of buildings in the city of Leiden is remembered by a waterside plaque.

The artwork is a community's ode to the "father of Irish tourism."

A rare surviving Victorian greenhouse designed specifically to house giant water lilies.

The city of Manchester quietly unveiled this tribute to a 19th-century massacre.

This colorful but controversial ceiling has been likened to a 21st-century Sistine Chapel.

One part local history, 99 parts gruesome haunted house.

Famously misunderstood wonder of the ancient world

Home to the world’s oldest seismograph and a four-ton steel ball that makes its own earthquakes.

This ornate church has survived Nazi and Soviet occupation, including a short stint as a Soviet-era gymnasium and cinema.

This military tunnel dates back to World War II and provides visitors with a little wartime adrenaline.

This striking structure is the Socialist-modernist centerpiece of a former Soviet spa resort.

Scars from the English Civil War mar this medieval sanctuary.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

One of the last examples of Soviet architectural propaganda has a few technological tricks up its sleeve.

This stately estate house features a tower covered in a bright, modern mural.

This charming Latvian lane doubled as Baker Street on the Soviet Union’s version of Sherlock Holmes.

Ride a boat through this magnificent underground world, which now doubles as a theater.

Every September, international competitors flock to a tiny Scottish island's flooded quarries.