Throughout history, humanity has undertaken ambitious projects that have pushed the boundaries of engineering and construction. These megaprojects, ranging from high-speed railways to massive hydroelectric dams, have transformed economies and shaped the modern world. Here’s a closer look at the top 10 costliest human-made builds, each showcasing ingenuity, vision, and sheer determination.
California High-Speed Rail (USA) – $100 Billion
Completion Year: Mid-2020s
The California High-Speed Rail is one of the most ambitious transportation projects in the United States. Approved in 2008 and spearheaded by WSP USA, this rail system aims to revolutionize travel between major Californian cities by significantly reducing commute times. Once completed, it will be the first high-speed rail system in the U.S., running at speeds of up to 220 mph.
Kashagan Oil Field (Kazakhstan) – $166 Billion
Completion Year: 2040s
Discovered in 2000 in the northern Caspian Sea, the Kashagan Oil Field is one of the largest oil reserves in the world, boasting approximately 38 billion barrels of crude oil. With an estimated 13 billion barrels deemed recoverable, this vast oil field is expected to remain a critical energy source until the 2040s. In 2013, China invested $5 billion for an 8.4% stake in the field, underscoring its global significance.
Channel Tunnel (UK & France) – $16.9 Billion
Completion Year: 1994
Originally proposed in 1802, the Channel Tunnel (or “Chunnel”) became a reality nearly two centuries later. Connecting the United Kingdom and France via a 31.4-mile underwater tunnel, it stands as one of the most impressive feats of civil engineering. This remarkable connection revolutionized travel and trade between the two nations, significantly reducing transportation time.
Three Gorges Dam (China) – $37.2 Billion
Completion Year: 2006
The world’s largest operational hydroelectric dam, the Three Gorges Dam, harnesses the immense power of the Yangtze River. Generating twenty times more electricity than the Hoover Dam, this project represents China’s commitment to renewable energy and flood control. However, it has also been a subject of environmental and social debates due to its large-scale displacement of local populations.
Hinkley Point C (UK) – $32 Billion
Completion Year: 2026
Situated in Somerset, England, Hinkley Point C is a massive nuclear power facility under construction. A joint investment by EDF (France) and CGN (China), this power station is poised to be one of the most advanced nuclear plants in the world. Once completed, it will play a pivotal role in the UK’s transition to sustainable energy.
AVE High-Speed Rail (Spain) – $1.69 Billion
Completion Year: 1992
Spain’s AVE (Alta Velocidad Española) high-speed rail system has been a game-changer for the country’s transportation. Launched in 1992, this rail network connects major Spanish cities at speeds reaching 192 mph. Before 2020, it carried over 20 million passengers annually, drastically improving connectivity and economic integration.
Dubailand (UAE) – $64.3 Billion
Completion Year: Ongoing
Set to become the world’s largest entertainment destination, Dubailand spans 107 square miles—twice the size of Walt Disney World in Florida. Envisioned to house numerous theme parks, resorts, and recreational attractions, the project was initially planned to include the towering Great Dubai Wheel. While construction slowed, Dubailand remains a testament to Dubai’s grand vision.
U.S. Interstate Highway System – $27.2 Billion
Completion Year: 1955
Spanning 47,622 miles across the country, the U.S. Interstate Highway System is one of the largest infrastructural developments in history. Signed into law by President Dwight D. Eisenhower in 1956, it revolutionized road travel and commerce in America. Today, it continues to serve as the backbone of the nation’s transportation network.
Honshu-Shikoku Bridge Project (Japan) – $3.6 Billion
Completion Year: 1998
Connecting the Honshu and Shikoku islands, this ambitious bridge system comprises 18 bridges, including the Akashi Kaikyo Bridge—the world’s longest suspension bridge. This project vastly improved connectivity, boosting economic growth in the region while standing as a marvel of modern engineering.
Hong Kong International Airport (China) – $20 Billion
Completion Year: 1998
Built on reclaimed land, the Hong Kong International Airport is one of the busiest and most advanced airports globally. When completed, it boasted the world’s largest passenger terminal structure. A further expansion plan, including a third runway, aims to meet increasing travel demands by 2030, potentially generating over 100,000 new jobs.
