Once thought to be the mysterious work of a witchy prophetess, a well with unusual properties turns objects into "stone".

This collection of ancient structures makes up part of the largest group of prehistoric earthworks in Britain.

Astonishing rock formations dot the Brimham Moor landscape.

One of the oldest and certainly best preserved Cistercian abbeys still in existence.

Where Agatha Christie mysteriously disappeared in 1926.

These megalithic tombs contain some of the largest stones ever moved in prehistory.

Rare karst landscape eroded from a flat seabed.

This medieval synagogue survived the Inquisition as a hospital and church.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

The final resting place of the great navigator, or maybe his brother.

A 16th-century Andalusian palace.

The world's largest wooden structure.

An eerie collection of the surviving structures from a past celebration of the future.

The Roman city was the birthplace of various emperors and is home to one of the empire's most impressive architectural feats.

The discovery of these rare, ancient artifacts led to the creation of a new museum.

The ruins of a 2,000-year-old Roman fishing village perched on one of the best beaches in Spain.

A Spanish town built into the cliffs.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Fighting the British and making game shows for over 150 years.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

This tiny river island switches sovereignty every six months as part of a rare, centuries-old agreement.

This technological marvel is one of the world's first 3D-printed bridges.