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

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

This architecturally eclectic fortress witnessed centuries of bloody turmoil, including the massacre of its ruling clan.

Luxury hotel turned into a refugee camp, then turned back into a luxury hotel.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

At this rare mosque in Tbilisi, Sunni and Shia Muslims pray side by side.

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

A neolithic dolmen that was rebuilt after collapsing during the 19th century.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

Banksy gives themself artistic license with this piece of London street art.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

Dr. Strangelove-esque tours reveal the inside a bunker once reserved for Stalin himself.

Home of the future Emperors of Russia.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Walk through Czech history in Prague's largest graveyard.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A sinuous path among steep cliffs creates a stunning sight in southwestern Serbia.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

The ancient Greek Titan guards this massive dam holding a lightning bolt to symbolize electricity.

The building is a gigantic piece of art inspired by the shape of a desert rose.

Nature's water park in the Wadi Bani Awf valley is full of pools flanked with cliffs and natural water slides.

This remote British Imperial telegraph relay outpost drove men insane.

Secret refuge and museum of the Duke of Florence.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.