The Louvre Pyramid took five years to complete. Designed in '84 and completed in 1989.

The Walter Pyramid took two years to complete. It’s 18 stories tall, and can seat 6,000 people. Each side of the perimeter of Walter Pyramid measures 345 feet (105 m), making it a mathematically true pyramid. It is one of only four true pyramid-style buildings in the United States, the others being the Summum Pyramid in Salt Lake City, Utah, Luxor Las Vegas in Las Vegas, Nevada, and the Memphis Pyramid in Memphis, Tennessee.

Pyramids are pretty simple. What you really want are today’s architectural wonders.

The Petronas Twin Towers are a pair of 88-storey skyscrapers standing at 451.9 m (1,483 ft) in Kuala Lumpur, Malaysia’s capital. They are the world’s tallest twin towers and were the tallest pair of buildings in the world after their construction in 2004. Both buildings are linked by a 2-story skybridge at their 41st and 42nd floors and the bridge is 170 m (558 ft) tall, which makes it the world’s highest 2-story sky bridge.

The Washington Monument is the world’s tallest stone structure, and the world’s tallest obelisk. It’s made of granite, bluestone gneis, and marble. It had a staggered construction, and took around 10 years to complete.

The Sydney Opera House took fourteen years to complete. Considered to be a modern masterpiece, it was the result of a competition and was opened by Queen Elizabeth II. It has also been featured in Star Trek as a hat.

The Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. Constructed between 1931 and 1936, during the Great Depression, it was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over 100 lives.

And so on and so forth