The largest medieval water tank on the Iberian Peninsula is preserved beneath the Cáceres Museum.

This influential Renaissance-era library was once the haunt of kings and monks.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

The ruins of an ancient stadium that hosted gripping chariot and horse races.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

Vibrant street art created with mixed media.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

Cliffside houses provide a spectacular view from their perch above the valley.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

Stunning Roman aqueduct used for 1900 years and still standing.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

The "Prussian Versailles" that is as glorious today as when it was built.

The fairy tale castle of the "fairy-tale king."

Where the father of Persian poetry is laid to rest.

18m long sarcophagus of a constantly growing dead prophet.

Where Stoddart and Connolly suffered in the infamous Bug Pit.

Time capsule of a museum, in which the Soviet Union remains alive and kicking.

If you want to get married in the White Marble City of Ashgabat, you should do it in this surreal disco ball building.

A huge monument to a bizarre book written by Turkmenistan’s longstanding dictator.

This harsh mountain path was built as a strange attempt to improve the health of Turkmen citizens.

Sumptous memorial to a controversial independence.