An ancient Egyptian temple in the middle of Madrid, Spain.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

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

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.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

The only museum with its curator—and her pets—buried inside.

Go inside to really appreciate this 500-year-old technological masterpiece.

Venice's "Island of the Mad."

This community on a small Venetian island has taken to painting their houses in bright neon hues.

Breathtaking and huge 430 year old maps of Italy.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

A Nesting Doll of Churches.

2300-year-old Roman road connecting the empire.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

This medieval city gate is now a blend of the past and the modern world.

The pockmarks across the building's facade are remnants of the Blitz.

Its collection includes a broad array of social, geographic, graphic design, and political history.