A hidden tunnel of bones in one of Malta's oldest churches.

This subterranean necropolis holds three floors of antler-dug grave caves.

This Stone Age solar temple aligns with the sun on each equinox and solstice.

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

Sloth rehabilitation center in the jungle of Costa Rica.

The sister plane of the C-123 shot down during the Iran-Contra Affair has found a new purpose in retirement.

Costa Rican accommodation resembles a crash site, but with a nice balcony.

The youngest volcano in Central America.

Believe it or not, the now-ubiquitous California avocado originated in Guatemala.

Central America's deepest lake is actually a volcanic caldera, surrounded by three volcanoes.

The remnants of an archaeological camp stand within Tikal National Park.

A massive underwater sinkhole made famous by Jacques Cousteau.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

Like something out of a pulp adventure, this abandoned plane wreck is slowly being retaken by the Caribbean jungle.

The floor of the oldest surviving synagogue in the Americas is entirely covered in sand.

The mouldering manses of wealthy colonials still pock the streets of a Curaçao neighborhood.

A safe place for the wild donkeys of a hot vacation destination.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

A naturally mummified 2,000-year-old man.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.