This beautiful building in the heart of Manhattan's Financial District was empty for decades.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

Giant topiary dog once played a role in a terrorist bomb plot.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Stunning Roman aqueduct used for 1900 years and still standing.

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 home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

A Gothic cathedral created from volcanic rocks.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

This beautiful deer park was built so King Charles I and his court could go hunting while escaping a deadly plague outbreak.

A wonderfully preserved example of London's 1960s-style high-density, low-rise public housing.

A cluttered and astounding collection of antiquities and curiosities.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

Since 1887, this old-school shop has stacked its shelves with extraordinary coffees and teas.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

A mysterious shape catches the eye in this 16th-century painting.