Every year, festive decorations appear on this juniper tree located in the median strip of a busy highway.

A geological mystery on Camelback Mountain.

Ancient pueblos built into the base of a natural canyon wall.

A former hospital is now home to a pizza parlor and maybe a few ghosts.

The world-record holder for the longest bridge stretching continuously over water.

A pink cottage covered in hearts served as a haven and a resting place for LGBTQ activists.

This symbolic piece of New Orleans architecture is also home to a few ghastly stories.

A collection of oddities including Dr. Kevorkian's suicide device, the Thanatron.

Though its celestial ceiling is impressive, the true star is the vast collection of French books.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

This castle-like building in Manhattan helped destigmatize cancer in the 19th century.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

This Art Deco masterpiece has stood in for some of the most famous buildings in comic book history.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

A whale rib was used to advertise the store by the arch that offered exotic goods from far away.

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

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

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

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

Pilgrimage site for star-crossed lovers.

Go inside to really appreciate this 500-year-old technological masterpiece.