The largest underground pedestrian tunnel system in the U.S. mostly caters to the people working in the offices above, but provides a great, air-conditioned way to traverse the city.

Rice balls symbolize fate and relationship at this adorable shrine, which was once dedicated to the Buddhist Devil.

Where visitors can play more than 150 retro arcade games.

A stretch of highway even lonelier than the so-called "Loneliest Road in America."

This unfinished tribute to a hometown hero and early baseball great is now an abandoned roadside attraction.

The site where the Emperor of Korea performed the long-forbidden "rite of heaven" to demonstrate his absolute sovereignty.

This saltwater swimming pool, which is the last of its kind in the United States, is slowly crumbling within sight of multiple high-end beachside hotels.

A sculpture capturing the emotional moment when a refugee boy realizes he is about to be deported.

This art gallery and oddities boutique bewitches visitors with a trove of occult trinkets and eccentric antiques, work by an ever-changing roster of underground artists, and classes in tarot and other mystic arts.

This depiction of the earth mother welcomes new life into Aurora Highlands.

An unfinished Serbian Orthodox church with 1,389 golden crosses planned to represent the Battle of Kosovo.

Inspired by a piece of concrete, these three pyramid-shaped buildings have been beloved Indianapolis landmarks for over 50 years.

An underground world of gorgeous, palatial metro stations designed as a nuclear shelter complex.

A two thousand year old brothel uncovered in Northern Greece.

An abandoned Byzantine fortress and notorious prison.

A little-known park with unusual, half-ruined structures and a mystical energy.

This architecturally eclectic early-20th century mosque was built as a place of worship for the Islamic followers of a Jewish messiah.

German-style coffee and cake, just like Oma used to make it.

This love letter to Poland serves bracing dill pickle soup and plump pierogis.

Hundreds of painted rocks dazzle this small beach where adding your own is encouraged.

This handsomely carved wooden church is more than 800 years old.

Sip sweet, luxuriously creamy Hong Kong-style milk tea at this cafe.

This no-frills joint has some of the most sublime Cantonese barbecue in town.

In the oldest zen temple stands a descendant of the very tree that introduced tea to Japanese culture.