One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

Week-long block party becomes a competition for the best decorated street.

Read a book next to a Midtown waterfall.

New York's oldest magic store.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

This North Carolina museum is keeping the pinball craze alive, with a little Space Invaders on the side.

London's marvelous wildfowl reserve along the Thames.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

A collection dedicated to the treatment of disease, held in London's oldest hospital.

Buried next to Pompeii, this lesser-known Roman villa was the opulent vacation home of Emperor Nero's wife.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The amazing wonder cabinets of a very rich Austrian archbishop.

This historic stone bridge has an entire neighborhood clinging to its sides.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

A wunderkammer of mysterious objects and stories.