Love is in the air along the small street in Brooklyn.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

One of the world’s largest cave systems houses legends, concerts, and wondrous rock formations alike.

It appears as if a man is standing behind this giant airport clock, painting the hands in real time.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

Amsterdam's former hotspot for public executions and dissections.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

This unattributed sculpture in Amsterdam is hiding in plain sight.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

American bombs, morbid memorabilia, and graphic photographs tell the story of the CIA-led “Secret War” from the Pathet Lao perspective.

More than 200 statues filled with cryptic symbols give this park spot an aura of horror vacui fantasy.

When the USA donated cement and funds to expand the airport in Laos, the Laotians built a massive monument instead.

An ancient iron pillar in Delhi that seems to be rustproof.

This abandoned stepwell is one of the largest, deepest, and certainly one of the creepiest in India.

The mysterious empty cupola behind the monumental arch points to an ancient prophecy of Delhi.

A startling, centuries-old subterranean marvel hides in plain sight.

A favorite with sightseers, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.

Two cannon-like cranes were installed on top of the bank building to fend off bad feng shui.

A serene space tucked amid the skyscrapers of Hong Kong's bustling financial district.

A striking depiction of Teotihuacan's mysterious "Spider Woman."

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.