Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

Humble beginnings for one of the world's most famous scientists.

This huge metal monument is slowly being stripped to its concrete skeleton.

Gargoyle head that brings good luck.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

A musical instrument played by the sea.

Shop for books in the New Orleans house where William Faulkner once lived.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

Decades before the scandal, this staircase on the river was a literal "water gate."

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

The oldest continuously operating fish market in the United States.

The national park was once a plantation estate.

Largest Roman Catholic church in North America.

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

Fittingly, America's museum of architecture is itself a magnificently designed old building.

Parking garage where Bob Woodward met Watergate source "Deep Throat."

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

At 207 feet, one of the world's longest continuous escalators.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Olfactory delights in San Francisco's Botanical Gardens.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.