Moscow's imposing monument to the Space Age.

Secret Soviet city once home to Russian cosmonauts and space training facilities.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

This striking, two-toned confluence of rivers is visible from space.

A beautiful opera house in the heart of Amazonia has recently restarted performances after a 90-year hiatus.

An art museum with an eclectic design and a scandalous past.

The massive gardens and office of a Brazilian sculptor.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

A notorious punk house turned co-op.

A curious fountain that has no water and includes Satan, a crab, and 9 giraffes.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

An abstract monument to a symphonic composer.

A subterranean house of worship carved right out of the bedrock.

340-foot statue built to honour the Heroes of the Soviet Union.

The deepest metro station in the world.

One of the largest museums in Ukraine remembers the story of the German-Soviet War in iconic, brutalist style.

The Guardian of Tallinn.

Flamboyant architecture from the turn of 20th century.

A black cat protests the City Guild in Riga's Old Town.

60 feet of towering steel balances gracefully.

An historic and oft-filmed spot for musclebound iron pumpers on the Pacific coast.

This hilltop park offers magnificent views and a Frank Lloyd Wright masterpiece.