There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

This cannonball embedded in the side of an Edinburgh house once served a surprisingly pedestrian purpose.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

An unusual resting place built into the hill with an amazing view of Lake Como.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

This stately bank building hides a spectacular star-studded ceiling.

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.

This peculiar Italian elevator runs both horizontally and vertically.

Psychoanalyst Carl Jung reported a paranormal experience after visiting this mosaic-lined Roman baptistry.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

A medieval, mosaic-lined baptistry built by a heretical Christian sect.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

Small on the outside, big on the inside, this church is an astonishing act of visual deception.

An exclusive waiting room built for the royal family in the 1920s is hidden in Milan’s central station.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

Claude Monet was baptized in this lavishly ornate Paris church.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This recessed garden protects thousands of mountain plants by creating its own microclimates.

With a history of slaughter, feast, and famine, remnants of the pork industry decorate this area--even its church.