Ingenuity. Imagination. Invention. These are the three criteria upon which we chose the seven greatest man-made marvels of the modern world. Not just the biggest or the most expensive projects, but the truest examples of engineering genius, architectural innovation, resourceful project planning, fearless workers, and overcoming adversity.
From bridges to dams to artificial islands, here is our list of the seven greatest and grandest engineering and construction achievements from the past 100 years.
#7 Hoover Dam (Black Canyon, AZ)
Named one of the Seven Wonders of the Modern World and a Historic Civil Engineering Landmark, the Hoover Dam rises 726 feet above the Colorado River and literally created Lake Mead — the largest man-made lake in the western hemisphere.
Started in 1931 and finished in 1935 at a price tag of $165 million, the Hoover Dam was the largest dam in the world at the time of its completion — requiring 4.25 million cubic yards of concrete to build. Crews dangled from ropes at heights of 800 feet or more during its construction. But the result was an engineering success: a dam with a base width of 1,660 feet and a crest width of only 45 feet.
But the Hoover Dam is much more than just a big concrete barrier; it also generates 4 billion kilowatt-hours of hydroelectric power every year, which is enough to serve the energy needs of more than a million people. And its total cost was repaid in full, with interest and then some, through the sale of its power.
#6 Millau Viaduct (Millau, France)
One of the greatest achievements in modern engineering, the Millau Viaduct is the world’s longest suspended bridge and the tallest cable-stayed road bridge anywhere. It measures 8,071 feet in length with a deck that stands 900 feet above the ground beneath. Each of its foundation towers stands 1,125 feet tall — nearly the height of the Empire State Building. And because of its enormous height, the bridge couldn’t be built in sections and then assembled into place. Instead, the roads were constructed on both side of the mighty towers and then rolled out to meet in the middle of the bridge.
Designed by French structural engineer Michel Virlogeux and British architect Norman Foster to handle the high volume of European vacationers, the Millau Viaduct was constructed in just three years (from 2001 to 2004) with a price tag of about $420 million.
#5 Palm Deira Island (Dubai, United Arab Emirates)
The Palm Deira Island made our list of construction marvels for its sheer ambition and imagination. As you can guess, beachfront property is extremely valuable in the Middle East, and there’s not too much of it in Dubai. So what did UAE Prime Minister Sheikh Mohammed Bin Rashid al Maktoum do? He literally built islands — three of them right off the coast, packed with world-class hotels, beachfront estates, marinas, amusement parks, shopping centers, and a 6-lane undersea tunnel that connects the islands to the mainland.
The largest of the three islands, Palm Deira, alone occupies 46.35 million square meters of land and required dredging three billion cubic feet of seafloor sand to shape its 17 palm-leaf inlet structures. It stands as the largest man-made island in the entire world.
#4 National Stadium, aka “The Bird’s Nest” (Beijing, China)
The National Stadium is definitely one of the most bizarre-looking structures on our list, but its unique design can also withstand a magnitude 8 earthquake. Built to host the 2008 Olympics in Beijing, “The Bird’s Nest” was built with over 16 miles of unwrapped steel, which weighed in at 42,000 tons. It’s 226 feet high, occupies 2.8 million square feet of space, and can hold 80,000 to 90,000 people (depending who you ask).
Designed by Swiss architects Jacques Herzog and Pierre de Meuron, the National Stadium is the most energy-efficient and environmentally friendly stadium in the world.
#3 English Channel Tunnel (London, UK, to Paris, France)
The English Channel Tunnel, also known as “the Chunnel,” is the longest underwater tunnel in the world. Spanning a length of 31.4 miles with a depth of 246 feet at its lowest point, the Chunnel connects England and France from beneath the English Channel.
Started in 1988 and completed in 1994, the tunnel takes travelers from London to Paris via a 100-mile-per-hour train in about 20 minutes. Although we don’t have an accurate amount as to how much it cost to build, we can tell you it’ll cost about $200 to take the trip today.
#2 Golden Gate Bridge (San Francisco, CA)
Quite possibly the most famous bridge in the world, the Golden Gate Bridge — started in 1933 and finished in 1937 — was built to connect San Francisco with the rest of the bay during the advent of the automobile.
The bridge boasts a beautiful art-deco design, and each of its two hulking main cables consists of 27,572 strands of steel cable — measuring about 80,000 miles long. With a cost of $35 million, the Golden Gate Bridge stretches nearly 9,000 feet in length, reaches over a mile, and required 600,000 rivets to put together.
Like many of the mega-structures built back in the 1930s, laborers faced horrible working conditions as well as a lack of safety measures, which resulted in 11 deaths during the span of its creation. Just the fact that this beautiful, old-world structure still carries 112,000 cars across it every day puts it at number two of our list of modern marvels.
#1 Burj Khalifa, aka “Dubai Tower” (Dubai, United Arab Emirates)
And finally, number one! Dubai has made our list of marvels yet again with the 2,717-foot Dubai Tower — holder of seven world records, including Tallest Building in the World and Tallest Free-Standing Structure in the World. It’s nearly twice as tall as the Empire State Building and three times as tall as the Eiffel Tower.
The tower consists of 163 habitable floors, 27 terraces, and touts one of the longest and fastest single-running elevators in the world — traveling almost three floors per second.
Twenty-two million man-hours went into building this behemoth between 2004 and 2010, with an average of 12,000 daily workers at its peak. Wind speeds of 99 mph during its construction made it both extremely dangerous as well as an engineering nightmare to build, especially with those heavy cranes that high up. And crew shifts didn’t let up when the sun went down; most of the concrete had to be pumped 2,000 feet straight upward during the nights due to the high desert temperatures during the day.