This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

This controversial Irish show cave is home to a massive formation known as the Great Stalactite.

The field of tiny caves that mark this Chinese cliffside are each their own historic Buddhist temple.

These numerous Israeli caves were dug out over hundreds years for reasons ranging from hideouts to burial sites.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

This tiny lake temple dedicated to a water goddess seems to float on the surface.

This Sumatran root bridge took almost 30 years to knit itself together.

This tiered waterfall is so pretty it may cause visitors to cry tears of their own.

The pedestrian traffic signals in Brazil's teeming metropolis light up with clues to nearby landmarks.

This Irish show cave is said to have been the site of a Viking massacre that claimed 1,000 lives.

This collection of lakeside pagodas and temples are flanked by giant lions, tigers, and dragons as well as their welcoming maws.

Discovered after draining a local pond, these ancient man-made caves are still a complete mystery.

This gruesome biblical parade celebrates the one day a year that a bit of Jesus' blood turns to liquid.

A waterfall runs right through the middle of this Taiwanese shrine to the hundreds of workers killed while building a nearby highway.

This Croatian fairytale castle is slowly falling apart thanks to years of neglect.

Hidden behind musical flora and forgotten for over a thousand years, this cave is now a neon dream.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

The programmatic glory of LA's giant whiskey barrel building has become an upscale reminder of the city's kitschy roadside past.

This luxury shopping lane has been protected by its own tiny police force for over a century.

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

This ultra-modern California span is actually a titanic solar clock in disguise built by famed architect Santiago Calatrava.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

There is only one place in the world where the corners of four nations come together.