This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

The stunning interior of this Gothic church is covered in ornate gold details.

A submerged village appears when dam levels drop.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

Oversized versions of a beloved toy dot a children's playground in a Spanish toymaking town.

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

Vibrant street art created with mixed media.

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

This house's itty bitty size means no humans allowed.

A celebration of solstice followed by a fiery purging of evils.

This mountaintop observatory is home to one of the world's largest reflective telescopes.

Infamous and now demolished panopticon prison built by its former inhabitants.

Just like in Hollywood, Madrid has also a forgotten walk of fame.

The remains of the second-oldest zoo in Europe can be seen within these library gardens.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

Stuck in the middle of a modern Madrid city block are the remains of a 19th century sports complex.

This lucky bronze frog was gifted to Madrid by a casino.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

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.