Constructed on the ruins of a convent, this tower saved countless lives.

What was once a unique system of urban elevators is turning into a mechanical ruin.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Haunted by its violent past, this colonial bastion was the largest Spanish military installation in the Americas.

This colonial town in Colombia sits around the largest stone paved square in South America.

This elegant Colombian fortress was one of the torture headquarters for the Spanish Inquisition.

Fenced off in a garden cemetery in Honduras lies the grave of the most notorious American filibuster.

A crumbling cathedral condemned by an earthquake.

This unassuming museum's slogan translates to “there is a limit of sadness, anxiety has no limits."

An Art Nouveau building covered in animal gargoyles and grotesques.

The deepest metro station in the world.

The haunting complex honors the millions of Ukrainians who died in the forced famine under Soviet rule.

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

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

Featured in one of the most iconic scenes in cinema history.

Monumental sculptures guard many of the graves, transforming this necropolis into an open-air fine art museum.

The only pub in the world surrounded by an ancient stone circle.

The largest stone circle in the world has ended up bringing up more questions than it has answered.

This bridge later moonlighted as a local jail.

One of the largest medieval barns in England and architecturally one of the finest.

This section of the Kennet and Avon Canal has been designated the same level of heritage protection as Stonehenge.

The plaques around this 19th-century structure recall some rather strange tales.

These ruins are a hidden gem, complete with fantastic views over the cliff edge.

This extinct volcano rises above Edinburgh and is special for its panoramic views over the city.