One of the few places in Portugal where the Celtic ritual of wearing large wooden masks is still practiced.

An 11th-century medieval castle cascades over the town of Numão.

These rock drawings in the Côa Valley also create an ancient optical illusion.

An ancient tomb that still stands in Portugal.

The medieval town's star-shaped walls are geometrically dazzling, though not entirely impenetrable.

One of the largest Roman settlements in Portugal.

Houses are tucked between, on, and underneath giant boulders.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

A windswept necropolis carved into the rocks overlooks the "most Portuguese town in Portugal."

Nestled in the mountains of Portugal is a tiny village made almost entirely of schist.

A majestic hotel for dreamers rises from the center of a fairytale wood.

A hidden tunnel leads to an abandoned slate quarry that's now a secret swimming spot guarded by cliffs.

This ancient castle has been abandoned since the Edwardian conquest of Wales.

Eerily lifelike effigies stare at everyone who enters this sanctuary.

This Welsh hotel is the spiritual home of the British 1953 Everest expedition, the first successful ascent of Mount Everest.

The remains of a small medieval chapel mark the legendary birthplace of the patron saint of Wales.

A Neolithic tomb hidden among a spectacular boulder-strewn stretch of coast.

Legends say that this small island was the final resting place of the Welsh saint of lovers.

The world’s only museum dedicated to baked beans.

The world's smallest movie theater runs on solar power—an attraction in itself.

The longest and tallest aqueduct in Britain can actually be sailed across.

This neolithic stone grave has been altered and restored so often its now more neo than lithic.

The remains of centuries of copper mining appear like an alien landscape.

These haunting ruins belong to an ancient village that once had one hell of a view.