Examines bizarre engineering achievements, including ball-like habitats in the Netherlands, an eccentric Colombian fortress built to last, and a strange train designed to conquer the towering Swiss Alps.

A look at some of the most impressive feats of extreme engineering, including an ancient town built in the Peruvian Andes, a thriving urban centre in Iran's scorching desert, and a city engineered to flourish in the frozen climes of Siberia.

Rural Brazil sees the devastating destruction of a dam; a bridge collapses catastrophically in Genoa, Italy; a once mighty ancient castle is reduced to ruins in Gaziantep, Turkey.

Presents an aerial tour of an engineering and mimicry marvel in London, Singapore's iconic Supertree Grove, and strange bubble-like domes in southern England.

Revealed from above; a massive bridge spanning a gigantic gorge in France; a record breaking outdoor elevator in China; and the world's longest tunnel carving its way deep beneath the Alps.

Revealed from above; The Pantheon - one of ancient Rome's most enduring and enigmatic feats of engineering; in Panama – a continent crossing canal that almost never was.

Revealed from above; an ancient temple engineered to survive the ravages of time; an iconic cathedral rising from the heart of Barcelona; and a remote, cliffside shrine that seemingly defies the laws of gravity.

Revealed from above; an ancient defensive wall surrounding a historic Colombian city; eerie metal towers looming over the seas of the English Channel.