This striking, two-toned confluence of rivers is visible from space.

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

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

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

A lush indoor jungle fills this bustling Madrid transportation hub.

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

A hidden three-foot-wide house separates these two regal churches.

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

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

Elaborate tile work in this railway station tells the story of Portugal.

This ship offers visitors the chance to spend the night aboard a former floating hospital for fishermen.

An icon of the city, this chapel features an amazing dome ceiling and offers panoramic views.

The ancient sauropod tracks found in this former quarry are some of the largest in the world.

In Portugal, a larger-than-life painting of America's first Black female firefighter.

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

Europe's largest collection of matchbox designs is a fascinating exploration of the cultural history of the world.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

In the summer, the area around this sculpture transforms into a vibrant concert venue.

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

This biographical museum honors the groundbreaking scientist at her birthplace in Warsaw.

The final resting place of more than 200,000 people, this is one of the largest cemeteries in Europe.

The world’s narrowest house makes for an awkward, four-foot-wide living space.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.