The unusual patterns in this rock formation result from two distinct modes of weathering.

The ruins of a 19th-century corn mill are haunted by a malevolent cave-dwelling spirit.

These ruins of an octagonal stone school that was later used as an A.U.M.P. church exemplify a popular school design from the 1830s.

The hallowed remains of a 900-year old Ancestral Pueblo great house.

A fantastic castle rumored to be the birthplace of King Arthur.

A partial tunnel blasted into a steep ridge is all that remains of a failed railway across Arizona.

Religious statues built because of one man's bargain with God fill this peaceful sculpture garden.

The fading, forgotten remains of a once bright and booming factory.

A stealthy Apache hideaway that became the haunting site of a mass grave.

Although now a decaying ruin, this stone cabin's history includes several notable figures.

A creepy statue of a hooded ghost hauls itself up from the water in a historic Lithuanian city.

A beautiful waterway tucked in the corner of a power plant.

You can row a boat through this ancient underground reservoir.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

Elevated freight railway turned wildly successful urban park.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

This former coal gasification plant found a curious second life as a popular public park.

A small canyon with petroglyphs and a seasonal waterfall, only a short hike from the remnants of old Route 66.

The artist James Turrell is repurposing an extinct volcano crater as an observatory to experience the cosmos.

Most-visited and most-photographed slot canyon in the American Southwest.

A toweringly silly piece of modern art has been delighting locals since the 1980s.

Iron Age grave stones and Viking burials, a short drive from Gothenburg.

Mounds, rune stones, and a 1,000-year-old church, left behind by Denmark's first two kings.

A stone in Wolin, Poland, marks the possible location of a legendary Viking fortress.