There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

360° views of the city plus five floors of optical illusions and hands-on science.

A gigantic statue of a Russian soldier watches over the ancient city of Plovdiv, a prominent reminder of the Soviet period in Bulgaria.

A vast Communist-era exhibition space in the Bulgarian capital.

"Holy Wisdom" overlooks the city that became its namesake.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

A striking symbol of the Bulgarian capital.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

The first museum in the world devoted to sexual gadgetry.

Macabre astrological automaton clock dating to the late 1400s.

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

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

The topiary maze at the Habsburg hunting lodge.

Inside a former cabaret, seven floors of erotic art.

The celebrated eyesore created by starry-eyed sweethearts.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

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

Paris' linguistic guide to the international language of, yes, love.

Christ's blood allegedly preserved in a Belgian town.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.