Fifteen years, five billion pounds and seventy-eight huge steel gates: this episode follows the project to build a vast sea barrier to protect Venice from flooding.

Engineers and architects attempt to raise the six central towers of Barcelona's Sagrada Familia, making it the world's tallest church, 140 years after maverick architect Antoni Gaudí began building it.

In Norway, Building Giants joins the international team of engineers and construction workers building the Hålogaland Bridge, the longest suspension bridge within the Arctic Circle.

Building Giants meets the engineers and workers building one of the largest and most advanced cruise ships in the world, the 1036-foot-long Meraviglia.

This episode meets the team building the world's most advanced sports arena - the Mercedes Benz Stadium in Atlanta - with the most ambitious retractable roof ever built.