Huge concrete structures designed as an early warning system for Britain to detect enemy aircraft.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

A solemn memorial in a majestic setting that honors a 1692 tragedy.

This World War II relic let Allied pilots know they were entering neutral airspace.

Two large posteriors in one giant statue.

Made up of 3,200 recycled glass bottles, this tree pays homage to Asturia's love of cider.

A charming Spanish village sits atop this natural limestone overpass.

This tiny museum's sizable collection is jammed into a former underground public toilet.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This beautiful, historic church looks like something out of a simpler past.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

Inside this Icelandic greenhouse, geothermal energy keeps tomatoes warm and growing.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

This wrecked airplane has been sitting on a black sand beach since the 1970s.

Three columns of volcanic rock shoot out of the ocean.

Walk in the footsteps of the gods and straddle two tectonic plates.

The atmospheric ruins of a historic church can be found on a hill above the city of Oviedo.

A historic Christian shrine nestled within a spectacular natural cave.

A spectacular walk on the flank of a gorge.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.