A miscalculation turns a very shallow freshwater lake into a very deep saltwater lake.

This famous bridge twisted itself into oblivion, but not for the reason you might think.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.

Miraculous tree that seems to sprout out of solid rock.

A cave's rare beauty held a cavernous secret hidden underground.

Resonating tubes make music from highway overpass.

Metal water storage tank turned ethereal concert hall.

The clock that sets them all.

Ancient human, animal, and geometric figures drawn in the earth.

A fake mine that was made using real mining techniques which is also used as a community center.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

A hollow cement depiction of time's inexorable effect on the human body.

Sandstone rock formations that look like they belong on the cover of a progressive rock album.

A long abandoned hospital building on the outskirts of NYC.

An abandoned stretch of highway, deteriorating next to the operational one.

A skeletal collection of former nautical mainstays.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

The smallest country in the world.

These strikingly barren, rolling red hills were caused by bad farming practices.

The rocks in this arid basin leave trails of movement behind them.