What comes to mind when you think of the world's largest construction projects? You'd be on the right track if you guessed airports, canals, and subways. There are also industrial complexes and utility projects. However, some of the current projects on the list may surprise you, such as the International Space Station and an entertainment park that represents Disney World.

1. Al Maktoum International Airport, Dubai

No other airport compares to Dubai's Al Maktoum International Airport, which covers an area of more than 21 square miles. The facility can accommodate 200 wide-body planes at a time. The second phase of the airport's expansion alone is expected to cost more than $32 billion. The newest expansion phase, which was supposed to be finished in 2018, has been postponed, with no definite completion date.

2.Jubail II, Saudi Arabia

Jubail II is a 22-year-old industrial city project with a $11 billion expansion budget that began in 2014. It will have at least 100 industrial plants, an 800,000-cubic-meter desalination plant, miles of trains, roads, and highways, and an oil refinery capable of generating at least 350,000 barrels per day when it is done. The project is expected to be completed in 2024.

3.Dubailand, Dubai

The Dubailand complex can accommodate three Walt Disney Worlds. The $64 billion Dubailand will be divided into six sections, each measuring 278 square kilometers: theme parks, sports arenas, eco-tourism, health facilities, science attractions, and hotels. With 6,500 rooms and a 10-million-square-foot mall, it will be the world's largest hotel. The project is expected to be finished in 2025.

4.International Space Station, Space

Every 92 minutes, the International Space Station (ISS) rounds the Earth. It was built by a consortium of 15 nations and five space agencies and is expected to cost more than $60 billion when completed. The space station's total cost, including planned additions, might reach $1 trillion, at which point it might be used as a habitat for up to 1 million extraterrestrials.

5.South-North Water Transfer Project, China

Although the north of China is home to about half of the country's population, it only has around 20% of the country's water resources. To correct this imbalance, China has funded the construction of three massive canals, each over 600 miles long, that will transport water from China's three major rivers to the north. The project will take 48 years to complete. It will provide 44.8 billion cubic meters of water each year when finished.

6.London Crossrail Project

The world's first subterranean rail system is expanding, with 26 miles of tunnel planned to connect 40 stations. Construction is expected to cost $23 billion. The project will be completed in stages, with the first new line, the Elizabeth line, planned to open in 2019, with the additional lines following in 2020.

7.High-Speed Railway, California

California's high-speed railway began construction in 2015 and is expected to be completed in 2029. It will run from San Diego in the south to San Francisco in the north, connecting eight of the state's ten largest cities. The project will be performed in two stages: first, the design phase, and second, the implementation phase. Phase 1 will link Los Angeles and San Francisco, while Phase 2 will link San Diego and Sacramento. The train will be 100-percent electric and will be powered entirely by renewable energy and capable of speeds up to 200 miles per hour.

8.Chuo Shinkansen, Japan

Japan's newest high-speed train line, the Linear Chuo Shinkansen, will run from Tokyo to Nagoya, a distance of 286 kilometers, in 40 minutes and at speeds of up to 505 kilometers per hour. This section of the high-speed route is expected to be completed by 2027. The line will be extended to Osaka in a later phase. The Tokyo-Nagoya line will be underground for around 86 percent of its length, requiring extensive tunnel construction. This magnetic levitation (also known as "maglev") train is the fastest train in the world.

9.Beijing Airport, China

In terms of cost, total square miles, and passenger and plane capacity, Beijing International Airport will eventually surpass Dubai's Al Maktoum International Airport. The first section of the airport was finished in time for the 2008 Olympic Games. The next phase of expansion is expected to be completed in 2025. The architect Zaha Hadid's Terminal 1 includes a number of sustainable design elements in a futuristic building envelope.

10.Great Man-Made River Project, Libya

Since 1985, Libya has worked on the "Great Man-Made River" (GMR) project. It is the world's largest irrigation project. When finished, it will irrigate over 350,000 acres of agricultural land and significantly enhance the amount of drinking water available in most of Libya's cities. The project's water comes from the Nubian Sandstone Aquifer System, which is underground.