An art installation commemorates journalist Nellie Bly's undercover reporting inside a New York asylum.

On this island, you suck away your garbage via an elaborate pneumatic tube system.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

A sculptural commentary on capitalism pokes up from the East River.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

A crumbling hospital from the 1850s on Roosevelt Island.

The first patented shaved-ice machine heralded a snowy wonderland of iced treats at a favorite New Orleans summer shack.

This fountain was designed to honor the man who helped bring water to Barcelona.

An early 20th-century bullring converted into a modern shopping center.

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

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.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

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

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.

Known as the "Grand Lady of Jersey City,” the city's first racially-integrated hotel was owned by a preacher who was, depending on who you ask, a cult leader, civil rights pioneer, or the manifestation of God.

This haunting monument honors the victims of 9/11.

This poignant display is now a memorial to these regionally extinct species.

Imagine having a street run right through your home, or better yet, a historic bridge three stories high.

This sculptural piece by the artist Tom Otterness doubles as a jungle gym.