Natural history museum celebrating biodiversity with a parade of taxidermy animals.

The narrowest street in Paris.

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

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

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

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

France's national museum of scientific and industrial instruments.

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

This museum houses an imposing skeleton army comprised of creatures great and small.

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

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

The oldest stone house in Paris was built by its most famous alchemist.

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

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

The only subway station in the city that still makes use of gap fillers.

The highest rapid transit station in the world.

The longest continuous underwater road in North America was built at the insistence of Franklin Roosevelt.

Lehigh Valley barge No. 79 still gets tugged along - but now it houses a museum and unusual performances.

On the hills of Bay Ridge stands a house straight out of a fairy tale.

Brooklyn vintners creating world-class wine in a city not known for its vineyards.

Twice a day one of these tragic bronze mariners drowns with the tide to remember all those the sea has taken.

A strangely angled West Village home is the only monument to an explosion that took the lives of three American revolutionaries.