Artist James Turrell's ode to dawn and dusk on the campus of Rice University.

Giant heads occasionally litter the industrial Houston neighborhood where sculptor David Adickes has his studio.

A taste of Middle Earth, in the middle of the Bayou City.

A modernist landscape of water and sci-fi concrete.

An ancient hotspot for spotting schools of fish.

Follow the original medieval paths that wind through this intriguing section of the city.

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

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

This massive mall has hundreds of shops, an amusement park, and a history of deadly amusement attractions.

This conservatory allows a little bit of the tropics to thrive in the middle of a major Canadian city.

The oldest continuously occupied public building in the United States.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Legend says train robbers stashed their gold within the depths of this unusual cave.

A reproduction of earth's many biomes.

A downtown park built on top of unclaimed graves.

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

The final resting place of the great navigator, or maybe his brother.

An emerald-green grotto just a short trip from Austin.

Home to an endangered salamander, a full moon celebration, and a large spring-fed outdoor swimming pool.

A little stop along the Texas highway where Rock Hudson, Elizabeth Taylor, and James Dean stayed while shooting the 1955 film "Giant."

Minimalist modern art on a repurposed military base in rural Texas.