Petronas Twin Towers

This guide to the Petronas Twin Towers in Kuala Lumpur opens underground, with engineers halfway through digging the foundations discovering a hidden geological edge running beneath the site of a former racetrack. It follows the decision that forced on the project, the record-setting pile-driving that came next, and Prime Minister Mahathir Mohamad's ambition for these towers on the world stage. You'll also hear about the two rival construction crews who raced each other upward, floor by floor, crane by crane.