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

Every equinox this Maya pyramid puts on a spooky ancient light show.

The location of this small park was once the site of an infamous public morgue.

Designed by Gustave Eiffel before his famed tower.

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

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

This embalmed man is one of the best preserved mummies from the Canary Islands.

An iconic and controversial ancient Iberian funerary urn with a hauntingly penetrating gaze.

A beautiful little museum hidden away in the heart of Barcelona holds a treasure trove of Ancient Egyptian artifacts

Barcelona's only remaining tram system takes riders to the Tibidabo funicular.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

This extinct volcano rises above Edinburgh and is special for its panoramic views over the city.

A never-finished memorial to the heroes of the Napoleonic War has become "Scotland's Folly."

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

Eighty million natural history specimens call this gargantuan museum home.

This unique rock formation is quite the local celebrity, although one day it may come crashing down.

Rumors and legends of secret Nazi activities surround this eerily remote island mansion.

Built on the foundations of an ancient Roman villa, the unique architecture of this castle on the Catalan coast was used as a set for 'Game of Thrones.'

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

Spain's largest bullring offers a unique glimpse at architecture and history.

Created as a "model concentration camp" to hide Nazi atrocities from the international community, this former camp-ghetto now holds a museum and memorial honoring the lives lost within.

Legend says this sacred tree was a gift from goddess Athena.