A Gothic cathedral created from volcanic rocks.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

This church sits upon a peaceful hill and a long, turbulent history.

Take a stroll through the hellish grotesques of Hieronymus Bosch in this elaborate Netherlands church.

A pilgrimage site where people ask Saint Dymphna to watch over those who are not of sound mind.

Perhaps the most beautiful of preserved saints, with a little help from Paris.

Lombardy poplars planted to imitate the size and shape of the Cathedral of Notre-Dame de Reims.

A modernist church in an ancient village.

This Netherlands museum holds a gloriously mechanical collection of ornate musical automata.

The attic of a four-century-old canal house hides a clandestine church.

Scale model of St. Peter's Cathedral (Rome) in the middle of a small Dutch town.

Sanctuary on a ridge near an ancient shrine to a "Black Madonna" built by the founder of Opus Dei.

This small museum collects the Christian remembrances which would otherwise be forgotten.

Beneath the city of Lourdes, France is a massive, concrete church.

1920's reinforced concrete church by architect Auguste Perret changes the face of modern design.

Huge Russian Orthodox cemetery in danger of being converted into open public space.

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

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

The largest underground church in Europe.

A Franco-era dam flooded (almost) everyone out of this centuries-old Aragonese town.

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

The tomb of a hard traveling saint is constantly covered in shoes as offerings to heal disabled youth.

The remains of this ornate chapel now act as a portal to a cramped French cemetery.

A French museum of wrought iron.