FOR THOUSANDS OF years, history has documented remarkable feats of building and manufacturing genius by engineers and architects. Ancient civilizations built memorials to empires. They knew no boundaries. They built mega structures and fortresses.

We are constantly asking “How did they do that?”

I don’t know what’s more incredible: the architectural and engineering feats of the civilizations thousands of years ago when they made do with primitive tools and manual labor, what our fellow men and women have accomplished the last 100 years or what today’s visionaries plan on doing the next 20 years.

What humans did centuries ago would be unbelievable if we couldn’t see for ourselves in relics of past empires left for us to explore. In many cases, we still can’t explain how they constructed those mega monuments. They are marvels of ingenuity. Some remain in forgotten places on Earth.

I want to give credit to the Science Channel. It broadcasts dozens of shows, but I urge you to watch “Modern Marvels,” “How It’s Made,” “Building Giants,” “Mysteries of the Abandoned” and “Extreme Engineering.” I think you also will be fascinated watching shows pertaining to the exploration of space and our oceans. What secrets do they keep?

For space devotees, how amazing are the scientists and engineers at Jet Propulsion Laboratory who built the rovers “Curiosity” and “Perseverance” being used in NASA’s Mars mission? Perseverance will leave July 17 on a seven-month journey to Mars, landing in February 2021. Team USA is racing Mars missions financed by China, the United Arab Emirates, and Europe and Russia.

As difficult as it is today to be a world-class stonemason, imagine what it took thousands of years ago when the Egyptians, Incans, Persians and Romans accomplished the impossible.

At the end of the 12th century, it took the efforts of close to a million people to build the Hindu Temple known as Angkor Wat in Cambodia. It took 30 years to build the temple complex for the Khmer Empire. Then and now, teams of engineers are convinced nothing is impossible. The answers just haven’t been discovered.

Top engineers and architects say a few of the most amazing feats are the Millau Viaduct; the International Space Station, which is the size of a football field; the Great Wall of China; the Great Pyramids of Giza; the Large Hadron Collider, which made physics breakthroughs possible; the Palm Islands of Dubai; the Three Gorges Dam; the Capital Gate in Abu Dhabi; the Burj Khalifa; the Florence Cathedral; St. Peter’s Basilica and the Taj Mahal.

Watch a marathon of How It’s Made. Notice the engineering genius of the machinery and computer-driven robots that give us a glimpse into the future. How did human minds conceive and build these magnificent machines?

The world’s best modern-day engineers and architects come from Germany, the United States, China, Norway, Denmark, South Korea, Brazil, Canada and Taiwan. Take note. Asian countries are betting future economic dominance on training engineers and architects.

Did you know the world is home to thousands of miles of tunnels? The most impressive man-made tunnels are in England, France, Norway, Japan, China, Malaysia and Turkey. Civilizations have been tunneling for centuries. They did it for survival and more recently, for getting through, under and over obstacles most would consider impossible.

Many major cities sit over major tunnel systems. Tunnels go under rivers, lakes, mountains and through miles of solid rock. The Science Channel shows you where they are and how they were built.

The longest tunnel that blows the mind is the Gotthard Base Tunnel which is 35.5 miles long and runs deep beneath the Swiss Alps. It took 17 years to build and cost more than $12 billion. In the United States, there is the famous Lincoln Tunnel in New York.

The Burj Khalifa in Dubai is the world’s tallest tower at 2,720 feet. They said it couldn’t be done.

The Millau Viaduct, a cable-stayed bridge, is the tallest bridge at 1,104 feet and is 8,100 feet long. It is located in southern France.

The Aswan High Dam in Egypt tames the Nile and was completed in 1970. It required the relocation of 90,000 Nubians.