This small glass cube is a peaceful out-of-the-way sanctuary at the busy airport.

One woman’s obsession gave birth to this lovely oddity at the Boston Public Library.

Radical Bookstore and Community Space.

Ralph Waldo Emerson spent two years living here decades before it became a Frederick Law Olmsted-designed park.

The often-overlooked ruins of one of the first buildings designed by famous landscape architect Frederick Olmsted.

This grand manse has been transformed into a museum devoted to one of the founders of Fantastic Realism.

The first modernist church in Europe.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

The housing complex served as an anti-fascist fortress during the Austrian Civil War.

Museum devoted to the artificial language of Esperanto.

Dine amidst exotic plants at this former royal greenhouse.

This museum promotes informed contraception by documenting its often secret past.

This cubist Vienna church building looks like some sort of alien stonehenge.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

Located right outside of Vienna, visitors can take in expansive views of an ethereal forest.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Macabre museum devoted to historical Viennese murders.

The final resting place for the remains of 143 Habsburg royalty.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

Diego Rivera hid various people and symbols in his first large-scale mural project.

A barbarous band of serpents guard the bases of these Aztec temples.

This ancient structure was built by a mysterious civilization that was largely destroyed by a volcanic eruption.