Artifacts and memories from the Vietnam war, located in a place that experienced it first hand.

Ho Chi Minh's perfectly preserved body has been on display here since 1975.

Walk through a clothing store, across a courtyard, and up several flights of stairs for delicious coffee with a side of beautiful views.

These crumbling towers are some of the last remnants of a centuries-old Vietnamese culture.

A nightmare for the claustrophobic lies hidden in Southeast Asia.

An extravagant monument to an extravagantly unpopular Emperor.

What looks like a normal building is really a hollow facade hiding a subway vent.

The recovered bones of martyrs slaughtered during The Terror are on display in this church crypt.

An off-the-beaten-path boutique stuffed with an eclectic collection of upcycled goods.

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

A subterranean shelter remains intact under a busy Paris railway station.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

Vienna's underworld of tunnels and subterranean rivers made an iconic appearance in a 1949 Orson Welles film.

The beautiful baroque library of the Hapsburg empire.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

These three pillboxes still remain as a witness of the Spanish Civil War in a park of Madrid.

This small museum tucked within a subway station holds pieces from Madrid's past.

A subterranean relic of the Spanish Civil War hides below this picturesque park.

This quirky curiosity shop takes its cues from the world's bazaars.

One of Savannah's oldest and most haunted cemeteries, featuring graves desecrated by Sherman's Union Army.

"X" marks the spot of an echo chamber in the middle of a plaza.

The remains of a chapel created for convenience.