Inside the corridors of this flea market, visitors are sure to find some obscure and odd treasures.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

The townhouse where the "Blood Countess" Elizabeth Báthory started her murderous career.

Apartment complexes built into huge repurposed natural gas tanks.

One of the best collections of wax anatomical models in the world.

A silly medieval mural preserved on the side of a Viennese house.

The resting place for anonymous victims of the Danube's dark waters.

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

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

Op-art architecture designed for happiness.

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

A spherical "micro-nation" in the heart of Vienna.

Dine amidst exotic plants at this former royal greenhouse.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

This former insane asylum now holds a pathological anatomy museum.

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

The beautiful baroque library of the Hapsburg empire.

Macabre museum devoted to historical Viennese murders.

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

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

This mansion oasis contains gardens, sculptures, and fountains just off the busy Plaça Kennedy in Sant Gervasi.

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

Barcelona's only remaining tram system takes riders to the Tibidabo funicular.