This legendary urban waterfall creates a dazzling display of rainbows.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

One of Hawaiʻi’s most notable historic petroglyph fields lies within a major resort.

A monument completed by a Third Reich sculptor in 1935 in Ankara's central park encourages Turks to "be proud, work hard, and have trust."

Resting place and mausoleum of the founder and first president of Turkey.

One of the earliest Ataturk monuments commemorates the victory of the Turkish War of Independence.

This 13th-century UNESCO-listed "lion's house" mosque is named after a repurposed lion sculpture.

A prison-turned-museum sheds light on modern Turkish history.

The metal spire on the roof of this tower was intended as an airship docking station, but it was never actually used.

Once one of the largest producers of pig iron in the world.

The first space rock known to have struck a human.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

An overlooked memorial honoring the local Washington residents who died in World War I.

Washington's iconic carousel has a nice piece of Civil Rights history.

This unassuming passageway played a key role in one of the most important events in U.S. history.

A former major munitions plant that has been converted into a sprawling art space.

The Lincoln Memorial has inspired many, even though a word on the inscription appears to be spelled incorrectly.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

Perhaps the most scandalous statue of America's first president.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

The 28,000-year-old specimen is remarkably intact.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.