Elvis's own personal tropical hideaway.

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

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

These azure waters were thought to lead to the Mayan Underworld.

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

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

After being lost for decades, this striking mural depicting the atomic bomb covers the wall of a busy Tokyo metro station.

Two stone columns flank the grand Venice square, but there were supposed to be three.

100 year tradition of fist fights, marked by marble footsteps.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

Thousands of slain Soviet soldiers are buried within the shadow of this enormous obelisk.

The menacing creature had a tremendous influence on the local culture before being exposed as a hoax.

This memorial plaque remembers a strangely shallow maritime disaster known as "Chicago's Titanic."

Once at the center of U.S. finance, the historic Trading Room was meticulously recreated piece by piece and rebuilt in the Art Institute.

This historic hotel invented the chocolate brownie.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

Once a black market electronics marketplace, now an otaku shopper's paradise.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

D.C. once had its own tiny rival to the New York Stock Exchange.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.