A Natural History and Science Emporium.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

A hidden "place of interment for gentlemen."

One of only two commuter aerial tramways in the United States.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

Mysterious 500-year-old tapestries depict a unicorn hunt.

Peek through the gates at this oasis from the city, full of Old English charm.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

On the top floor of an upscale department store stands a lavish restaurant housed in a replica of a luxury French dining car.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

Read a book next to a Midtown waterfall.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

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

This bridge was constructed from the rubble of the infamous Bastille.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

The first green space constructed on an elevated viaduct.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

How did a French journalist’s grave become the sexiest statue in the cemetery?

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

Dedicated to the art of hunting, with juxtapositions of contemporary art.

The history of radiation is on safe display at the foot of a radiation science laboratory.