New York's Brooklyn Bridge might be the most important bridge in the world, and it took dangerous, cutting-edge engineering to built it. Experts use the latest tech and modern-day science to reveal if building it a second time would be just as deadly.

Rome's Colosseum is the most famous stadium on the planet, and it took cutting-edge engineering and a fallen emperor to build it. Experts use the latest tech and modern-day science to reveal if building it a second time would be just as difficult.

According to the Bible, Noah's Ark was a world-changing engineering feat, and it took cutting-edge construction to build it. Experts use the latest tech and modern-day science to reveal if building it a second time would be just as difficult.

Rome's aqueducts are one of the greatest engineering marvels in history, and it took dangerous, cutting-edge construction to build them. Experts use the latest tech and modern-day science to reveal if building them a second time would be just as deadly.

The Great Wall of China is one of the world's greatest engineering marvels, and it took dangerous, cutting-edge construction to build it. Experts use the latest tech and modern-day science to reveal if building it a second time would be just as deadly.

Rome's Pantheon hides the secret to the Roman Empire's power, and it took dangerous, cutting-edge engineering to build it. Experts use the latest tech and modern-day science to reveal if building it a second time would be just as deadly.

Experts use today's technology in figuring out if building Venice today would be as dangerous as it was before.

When catastrophic fires ravaged Notre-Dame in April 2019, one of the world's great wonders was left in ruins. Experts use the latest tech and modern-day science to reveal what it will take to build it a second time.