An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.

A quirky bookstore hidden beneath a sea of whitewashed Greek villas.

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

An ancient octagonal weather station named for the eight Greek gods of wind.

Where once there was a train station bathroom, there is now this German burger joint.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

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

A spectacular cave and a beguiling lake.

This tourist village in Nairobi celebrates the traditional lifestyles and customs of Kenyan tribes.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

Deliberately hidden for centuries, the magnificent Saadian Tombs were eventually uncovered in 1917.

The oldest monument in Marrakesh and the city's only surviving example of Almoravid architecture.

Morocco's Argania trees are infested with nut-hungry goats.

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

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

Where Venice's gondolas go for a tune-up.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

The celebrated eyesore created by starry-eyed sweethearts.

This bridge was constructed from the rubble of the infamous Bastille.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.