Religious dwelling in a Spanish volcano.

A Romanesque tower appears when water levels drop.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

Mountain where Jesus was first tempted by the Devil.

This cemetery features modernist statues as strange as its name.

A contemporary art installation housed within a Gothic cathedral.

This religious complex carved into a cliff is steeped in legends of miraculous stags and the Holy Grail.

A magnificent place to see authentic paleolithic cave paintings that are an astounding 33,000 years old.

Disturbing winged beings decorate the walls of this strange abandoned hermitage.

The site of a legendary battle immortalized in medieval literature.

An out-of-place grove of sequoias thrives in northern Spain.

This magnificent brick dome was made with an unusual design method.

A Franco-era dam flooded (almost) everyone out of this centuries-old Aragonese town.

The walls of these four caverns are filled with art that dates back to the earliest human presence in Europe.

This 19th-century fountain's namesake animal isn't what you think it is.

A charming Spanish village sits atop this natural limestone overpass.

Translating as "The Jump of the Girlfriend," this stunning waterfall has a tragic legend behind it.

A landscape decorated with enormous skull sculptures.

An unusual but excellent display created in the 1930s as propaganda against the Freemasons.

A hidden medieval crypt where a famous legend says the devil used to teach black magic.

The gaunt visage of this angular Christ giant is enough to put the fear of God into all who see it.

One of the largest ossuaries in Spain is packed from floor to ceiling with bones.