Top 10 Most Expensive Projects in Human History Ever

King Abdullah Economic City is a rapidly growing investment hub with a modern infrastructure, offering world-class tourism and urban living experiences. As a key driver of Saudi Arabia's Vision 2030, the city is expected to cost an estimated $86 billion upon completion. Located along the Red Sea coast, this emerging city will include the world-renowned King Abdullah Port, recognized by the World Bank as one of the most efficient ports globally. It will also feature the Industrial Valley, focusing on light manufacturing and logistics, along with luxury hotels, villas, prestigious universities, and a major airport.

The city is being developed by Emaar Properties, the renowned real estate group behind the Burj Khalifa in Dubai. Part of an ambitious '10x10' program, the city aims to position Saudi Arabia as one of the top ten global investment destinations by 2010.

Dubailand is renowned globally as an entertainment complex planned for Dubai, United Arab Emirates, owned by Tatweer (a subsidiary of Dubai Holding). Announced in 2003, the Dubailand project was one of the most ambitious entertainment developments in the world, initially budgeted at $64.3 billion. Construction was paused in 2008 due to the Dubai financial crisis, but resumed in 2013. To date, Dubailand has cost investors a staggering $76 billion. Once completed, it is set to become one of the largest and most expensive entertainment facilities globally, with plans for a Disney theme park, an IMAX theater, and many other attractions. The design elements of Dubailand will draw inspiration from Arabian folklore, particularly the tales of One Thousand and One Nights. The mega-project emerged from the belief that Dubai needed a major family-friendly attraction to compete with other tourist cities.

Dubailand has become one of the most popular districts in Dubai, resembling a city within a city, featuring a theme park, polo clubs, hotels, and various housing developments. As a free zone, Dubailand is also known for its affordable villas.

Over the past decade, architects and urban planners have worked together to design Songdo, a groundbreaking new commercial hub that showcases South Korea's advancements in technology and infrastructure. Once hailed as a model for future urban living, Songdo is built on reclaimed land off the coast of Seoul and is valued at over $40 billion.

Songdo International Business District aims to be a unique 'smart city,' offering universal Wi-Fi, automated recycling plants, and other technological innovations. The district will feature replicas of famous landmarks, including one of Central Park. Additionally, a small island with rabbits and deer will add a natural touch. Songdo IBD is being developed to attract businesses and tourists, and is conveniently located near Incheon International Airport.

Songdo is seen as an extension of Incheon, a major international transportation hub that ensures easy access for both local and global travelers. Developed in the early 21st century, Songdo is designed as a high-tech, sustainable city with a vision for a future free of cars, pollution, and overcrowded spaces.

The California High-Speed Rail is a public-funded project currently under construction in California. In 1996, the California Legislature and Governor Pete Wilson established the California High-Speed Rail Authority to plan and seek approval from voters for the system. Construction began in 2015, with Phase 1 expected to be completed by 2029. The project has exceeded its initial budget.

This rail system is the first of many initiatives that aim to fulfill one of President Obama's early promises: to connect major U.S. cities with high-speed rail. Project head Jeff Morales stated that while the cost will exceed $33 billion—more than initially projected—costs are expected to decrease due to emerging technologies.

The first phase will connect Merced to Bakersfield, with plans to eventually link San Francisco and Los Angeles. The rail will support speeds up to 220 miles per hour. The California High-Speed Rail system is expected to offer environmental benefits by reducing pollution and carbon emissions, as well as improved traffic flow, decreased congestion, and economic benefits, especially in California's Central Valley.

Kansai International Airport is the primary international airport serving the Greater Osaka area in Japan, located on an artificial island built to withstand frequent earthquakes and tidal waves. Situated in Osaka Bay off the coast of Honshu, it lies 38 kilometers southwest of Osaka Station, within the municipalities of Izumisano, Sennan, and Tajiri, in Osaka Prefecture. The airport was strategically constructed offshore to minimize noise complaints. The estimated cost of building Kansai International Airport was $29 billion.

The airport serves as the international hub for three major Japanese airlines: All Nippon Airways, Japan Airlines, and Nippon Cargo Airlines, and is also a key hub for Peach, Japan’s first low-cost international carrier. In 2016, Kansai saw 25.2 million passengers, making it the 30th busiest airport in Asia and the third busiest in Japan.

Today, Kansai International Airport has become a key transportation hub in Asia, with 780 weekly flights to destinations across Asia and Australia, including 119 cargo flights, 59 flights weekly to Europe, 5 flights to the Middle East, and 80 weekly flights to North America. In 2020, Kansai earned accolades from Skytrax for Best Airport Staff in Asia, Best Airport Staff in the World, and Best Airport for Baggage Handling.

The Big Dig was a planning nightmare and an overwhelming budget disaster, costing taxpayers approximately $23.1 billion. Larger in scope than the Panama Canal, Hoover Dam, and the Alaskan Pipeline, the Big Dig involved rerouting major highways through the heart of one of the country's oldest cities. The main artery of Boston's road network, Interstate 93, was redirected underground beneath the city's downtown in a section called the Thomas P. O'Neill Jr. Tunnel.

Led by Bechtel/Parsons Brinckerhoff, one of the largest and most experienced infrastructure design and construction teams, the project was backed by extensive environmental studies, risk assessments, and other preliminary documents. Despite these efforts, costs escalated across all contracts throughout the project's lifespan, with extensive attempts to mitigate risks and control expenses.

The project faced significant financial and administrative hurdles, including major design errors that led to nearly $400 million in compensation payments. Tragically, a fatal accident occurred when a concrete panel fell onto a car from the ceiling of the Fort Point Channel Tunnel. Various obstacles delayed the project, including sunken ships that required anthropological analysis before they could be relocated. The Big Dig ultimately finished more than a decade behind schedule, with costs running millions over the original budget.

Also known as the "Chunnel," the Channel Tunnel runs beneath the waters separating the southern coast of England and the northern coast of France. Completed at a cost of approximately $22.4 billion, it was funded by 15 French and British companies and is operated by Eurotunnel. Increasing safety, security, and environmental demands led to the final cost exceeding 80% of the initial estimate. The Channel Tunnel remains the only fixed connection between Great Britain and mainland Europe.

Spanning 37.9 kilometers, the Channel Tunnel holds the record for the longest underwater tunnel in the world and is the third-longest railway tunnel globally. Tunnel boring machines began excavating in 1988, and by 1994, the tunnel was operational. Tragically, ten workers lost their lives during construction. The tunnel consists of three parts: two rail tunnels with diameters of up to 25 feet and a service tunnel with a 16-foot diameter, each tunnel stretching 31 miles beneath the sea.

There have been several fires in the Channel Tunnel, some of which resulted in injuries and led to service suspensions for months. Security forces have also intercepted numerous attempts by people trying to enter the UK illegally by hiding inside vehicles transported by Eurostar trains.

The United States Interstate Highway System stands as the most expensive project in human history. As of 2015, it had cost taxpayers approximately $459 billion. The president most associated with its creation is Dwight D. Eisenhower, whose vision extended beyond transportation; he saw it as crucial for national defense, enabling quick military mobilization in emergencies.

Initiated in 1956, the project involved constructing new routes and converting old roads into federal highways. Nebraska was the first state to complete its portion of the system, finishing in 1974, while the final stretch, I-70 through Colorado, was completed in 1992.

Despite vastly exceeding initial cost estimates and taking years longer than expected to finish, the United States Interstate Highway System has greatly benefited the nation and its economy. It has reduced shipping costs by an estimated 17% for businesses, and during Hurricane Katrina, the system's reverse-flow measures were vital for speeding up evacuations from New Orleans.

The International Space Station (ISS) is the largest modular space station in low Earth orbit, with a cost of approximately $150 billion to complete. This massive project involved five space agencies: NASA (USA), Roscosmos (Russia), JAXA (Japan), ESA (Europe), and CSA (Canada). Russian rockets and the Space Shuttle were primarily used to assemble the ISS, with each module built on Earth before being sent into space for assembly. The station was uncrewed until two years into construction when the Russian Zvezda module was added, providing the necessary life support systems and crew quarters.

The ISS is served by a variety of visiting spacecraft, including Russia's Soyuz and Progress, SpaceX's Dragon 2, and Northrop Grumman's Cygnus. Previously, it also hosted the European ATV, Japan's H-II transfer vehicle, and the original SpaceX Dragon. These spacecraft transport cargo, including pressure-sensitive items like scientific experiments, back to Earth for further analysis.

As a laboratory for research in space environment and microgravity, the ISS conducts scientific experiments in areas such as space biology, astronomy, meteorology, physics, and other fields. The ISS also serves as a testing ground for spacecraft systems and equipment needed for potential long-term missions to the Moon and Mars in the future.

The Kashagan Oil Field is an offshore oil field located in the Caspian Sea, Kazakhstan. Discovered in 2000, it is situated north of the Caspian Sea near Atyrau and is considered the largest oil discovery in the past 30 years, along with the Tengiz field. At the time of its discovery, it was the second-largest oil field in the world. The field has cost approximately $116 billion to develop, making it the most expensive energy project in history. The recoverable reserves are estimated at around 13 billion barrels of crude oil, with expected production of over 90,000 barrels per day starting in 2017. The total recoverable oil in the field is projected to be a massive 13 billion barrels.

Extreme conditions, including sea ice in winter, temperature variations ranging from −35 to 40 °C, shallow waters, and high hydrogen sulfide content, coupled with poor management and disputes, have made Kashagan one of the most challenging super projects in oil extraction. Kashagan has been designated as a major source for the Kazakhstan-China pipeline. Key partners in the development include Shell, Exxon Mobil, Total, China National Petroleum Corp, KazMunaiGas, INPEX, and AgipKCO, with Shell overseeing the production phase.