An apparition of Virgin Mary in Herzegovina.

The naturally mummified body of a peasant girl saint.

This popular pilgrimage site offers a hole filled with holy healing dirt.

The world's toughest modern Christian pilgrimage leads directly to the gates of Hell.

An ancient holy well said to be used by the patron saint of sailors and travelers, lost in the boggy west of Valentia Island.

The oldest continual pilgrimage site in Britain was supposedly created by a gruesome beheading.

A subterranean playground in an abandoned slate mine.

Britain's only artificial surfing lake is nestled in the beautiful mountains of Wales.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

The studio of Catalonia's most famous theatrical designer remains exactly as he left it.

A temple to modernity, tucked away amid Barcelona's more well known museums.

A stately palace has been converted into the world's largest cannabis museum.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

This cemetery features modernist statues as strange as its name.

This semi-secret storybook hedge maze is also the oldest garden in the city.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

High atop a Mexican rainforest mountain, this ancient pyramid once drew pilgrims countries away.

A uniquely robust and historic look at Mexico's omnipresent dance with Death.

Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

Frida Kahlo's childhood home, now a museum of her life and works.