A beautiful opera house in the heart of Amazonia has recently restarted performances after a 90-year hiatus.

An ancient Egyptian temple in the middle of Madrid, Spain.

The remains of a convent turned military barrack in the heart of Madrid.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

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

Commonly acknowledged as the only public monument to the Devil himself.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

Inside this metro station is a section of the city's former medieval fortification.

This hotel was once home to a steamliner company and became the final rest stop for Europeans heading to the New World.

Four giant movable street lights decorate this modern Rotterdam square.

This old KLM airplane cut into three parts was transformed into an eclectic airport gift shop.

Atop this former dutch railway office sits an interstellar work of art.

An idyllic hotel that gave its name to a supposed shadow government.

A modern reimagining of a medieval city gate.

For the holidays, the tallest broadcasting tower in the Netherlands turns into one of the world's tallest Christmas trees.

'The Letters of Utrecht' lays out a ribbon of poetry one letter at a time, with no final verse in sight.

This medieval castle was painted pink as part of a now-abandoned children's theme park.

A set of 27 bamboo tubes creates an eerie soundscape that changes with the wind.

Yup, that's a 330-foot yacht passing over the highway.

This historical Netherlands fortress still bears the marks of its single siege.

Go inside a revolutionary, cage-less zoo where 35 species live and some of them roam free alongside their human visitors.

Take a stroll through the hellish grotesques of Hieronymus Bosch in this elaborate Netherlands church.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.