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

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

Mountain where Jesus was first tempted by the Devil.

Museum housed in underground tunnels that date back to Buenos Aires's earliest settlements.

A gateway to a mysterious network of underground tunnels.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

Rebuilt remains of a temple to Roman god Mithras.

Hear the quietest sound from across the dome.

This landmark church concealed a crypt packed with bones that was discovered thanks to the London Blitz.

An unusual round church in London with a Templar past.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

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