The Victorian-era greenhouse is stuffed with tropical plants, and open 365 days a year.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

Scars of this building's past life as a violent prison still cover its walls.

A Bronze age settlement on the Greek island of Santorini might have been the inspiration for Plato's Atlantis.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

This legendary city has been a tourist attraction for centuries.

Monasteries on rock pillars, once accessible only by frayed ropes.

There aren't too many operational funiculars around, but Pittsburgh has two!

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

House of vintage taxidermy and Steampunk sculptures in a quiet Pittsburgh neighborhood.

A beautiful oddities shop crammed with strange and morbid curiosities.

An 18th-century Catholic church converted into an eccentric temple of music and bacchanalia.

With 3,000 bikes on display, the world's largest bicycle museum includes some famous rarities.

This public park was the site of the largest civilian disaster of the Civil War.

A sealed test tube said to hold Thomas Edison's dying breath was given to the inventor's friend and mentee, Henry Ford.

Inside houses a vast collection of military aircraft and missiles spanning the ages.

This Memphis recording studio launched the careers of Jerry Lee Lewis, Johnny Cash, and Elvis Presley.

Home to drunken tower-climbing goats... seriously.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

This whimsical campus lawn is dotted with large sculpted numbers and hidden mathematical formulas.

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

The final resting place of New Orleans' most famous voodoo priestess.