The world's largest wooden structure.

A 16th-century Andalusian palace.

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

Pilgrimage site for star-crossed lovers.

A Hawaiian stairway to heaven—that you can't climb.

During the solar phenomenon "Lahaina Noon" this bendy, curvy sculpture forms a perfectly circular shadow on the ground.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

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

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.