Top 10: Biggest Construction Projects in the World
From a dam in Tibet that dwarfs anything previously built, to an entire city rising from the Indonesian rainforest, the world's largest construction projects in 2026 span six continents and push the boundaries of engineering.
This list is based on the physical scale and scope of the project, rather than just the cost, and includes some of the most ambitious and technically demanding building projects of all time.
Many of these megaprojects have budgets that run into the hundreds of billions, and some are still being built long after their original completion dates have passed.
10. Dubailand
Location: Dubai, UAE
Total cost: US$64.3bn
Dubailand is one of the largest planned leisure destinations on earth, spread across 278 square kilometres between Sheikh Mohammed bin Zayed Road and the desert.
When completed, Dubailand will comprise six differently themed worlds that include theme parks, sports venues, hotels and residential districts, plus what was originally planned as the world's largest hotel. Progress has been stop-and-start, with phases paused and restarted over the years.
Innovative technologies such as 3D printing and robotics have been used during the build, alongside sustainability targets including net-zero emissions and water recycling.
9. California High-Speed Rail
Location: California, US
Total cost: US$89-128bn (Phase 1)
Venetian Resort in Las Vegas.
The largest public infrastructure project in US history, California's high-speed rail will eventually span 800 kilometres from San Diego to Sacramento.
Active construction is concentrated on the 171-mile initial segment between Merced and Bakersfield, where more than 80 miles of guideway are complete, and track installation contracts were awarded in June 2026.
Cost estimates for Phase 1 have risen from the original US$33bn to between US$89bn and US$128bn, with federal funding withdrawals of more thanUS$5bn under the Trump administration complicating matters.
The latest projected completion date for the Merced-Bakersfield initial service is now 2033.
8. Jubail II
Location: Jubail, Saudi Arabia
Total cost: US$80bn
Jubail II is a sprawling, 6,200 hectare expansion of the Jubail Industrial City, which is creating a global energy and chemical hub in the heart of the Arabian Gulf.
The site is designed to accommodate petrochemicals manufacturing, clean hydrogen production, carbon capture and ammonia plants, and major energy companies including Shell have been involved at various stages.
The target is full operational status as a global industrial centre by 2035, when it will become one of the largest petrochemical complexes on the planet.
7. Nusantara
Location: East Kalimantan, Indonesia
Total cost: US$32bn+
Indonesia is building an entire new capital city from scratch on Borneo, relocating the government from the subsiding and overcrowded city of Jakarta.
Construction began in 2022, and the core government district already includes completed ministry buildings, a presidential palace, hotels and housing for civil servants.
Nusantara is designed to be a smart green city that will be powered primarily by renewable energy, and will feature extensive wildlife reserves.
Ambitions have been scaled back under President Prabowo Subianto, who downgraded the city's status and cut state funding. Approximately 10,000 people currently live and work at the site.
6. South-North Water Transfer Project
Location: China
Total cost: US$62bn
China's South-North Water Transfer Project redirects water from the Yangtze basin to the much drier and heavily populated northern regions of the country.
When fully-built, it will divert up to 44.8 billion cubic metres annually through canals, tunnels and pumping stations stretching thousands of kilometres. The eastern and central routes are operational but the western route is still under construction.
State contractors including China Railway Group are among the principal builders and the project is expected to take 50 years to complete in full.
5. King Abdullah Economic City
Location: Rabigh, Saudi Arabia
Total cost: US$100bn
King Abdullah Economic City covers 173 square kilometres on the Red Sea coast and will eventually house two million people.
It includes one of the region's largest deep-water seaports, an industrial zone and a central business district.
In May 2025, Emaar, The Economic City awarded a US$145.9m infrastructure contract for works at the Industrial Valley and Special Economic Zone, including the first phase of the King Salman Automotive Cluster, a dedicated automotive manufacturing hub.
4. Al Maktoum International Airport expansion
Location: Dubai, UAE
Total cost: US$35bn+
Al Maktoum International Airport is being expanded into the world's largest airport by developer Dubai South, covering 56 square kilometres with a target capacity of 255 million passengers per year.
The project includes five runways and four terminal buildings, covering a site that is larger than many city centres. Once completed it will surpass Dubai International in both size and throughput, with all Emirates and Flydubai operations relocating from Dubai International to Al Maktoum International Airport.
Construction is advancing in phases, with full completion expected into the 2030s.
3. Gulf Cooperation Council Railway
Location: Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, UAE
Total cost: US$250bn
The GCC Railway will link all six Gulf Cooperation Council member states across a 2,177-kilometre network, providing the first direct rail connections between countries where long-distance travel currently requires flying or driving.
Passenger trains will run at speeds of up to 200kph, cutting the Abu Dhabi to Dubai journey to under an hour.
Kuwait signed a US$8m design contract with Turkish firm Proyapi in April 2025, advancing one of the network's last unresolved sections. Saudi Arabia has separately tendered the US$7bn Saudi Landbridge, a 900-kilometre line connecting Riyadh and Jeddah that will integrate with the wider GCC network.
China Railway Construction Corporation is among the major contractors involved. GCC Secretary General Jassim Al-Budaiwi confirmed in January 2026 that the railway is expected to be completed by 2030.
2. NEOM
Location: Tabuk Province, Saudi Arabia
Total cost: US$500bn+
NEOM is the largest construction zone in the world in terms of area, spanning 26,500 square kilometres of northwestern Saudi Arabia, which is roughly the size of Albania. Sub-projects include Oxagon, a coastal industrial port, Trojena, a mountain tourism destination, and Sindalah, a luxury island that was around 75-80% complete by early 2026.
The centrepiece is The Line, a planned 170-kilometre linear city that made global headlines when it was announced in 2021. However, construction was suspended by the Public Investment Fund in September 2025 after an internal audit projected costs of US$8.8tn, and a completion date of 2080. Only 2.4 kilometres of foundation work had been completed when work stopped.
The project has since pivoted towards green hydrogen and AI data centre development, with an US$8.4bn hydrogen plant at Oxagon around 80% complete in early 2025. NEOM has spent an estimated US$50bn to date across all components.
1. Medog Hydropower Station
Location: Tibet Autonomous Region, China
Total cost: US$137bn+
Construction began on the Medog Hydropower Station on 19 July 2025, when Premier Li Qiang presided over a groundbreaking ceremony in Nyingchi City. At 60 gigawatts of planned installed capacity, which is nearly three times that of the Three Gorges Dam, it will become the most powerful hydroelectric facility ever built.
The project harnesses the Yarlung Tsangpo River at its Great Bend, where the river drops 2,000 metres across 50 kilometres through the Earth's deepest canyon, before crossing into India as the Brahmaputra.
Four 20km tunnels are being bored through Namcha Barwa mountain to divert the river, and annual output is projected to be 300 billion kilowatt-hours.
The project is owned and developed by Power Construction Corporation of China, with commercial operations planned for 2033.
It has sparked significant geopolitical concern in India and Bangladesh, both of which depend on the Brahmaputra as a primary water source, with many concerned about the fact that China will effectively control the flow of a river on which 130 million people rely.
