Governments around the world are currently spending billions on megaprojects that will change their countries forever, from new capital cities to rail links to border walls to the world's largest collection of theme parks. Click or scroll through some of the most ambitious plans and their staggering costs.

Egypt's pristine new administrative capital (NAC), which is yet to be formally named, is taking shape in the desert 28 miles east of Cairo. Conceived in 2015, the idea was given the green light as a way to deal with rapid population growth in Cairo. Construction on the first phase began in 2017, which alone is slated to cost $45 billion (£38.6bn), and the second phase reportedly kicked off in September 2020. The meticulously-planned solar-powered city will seriously impress with supertall skyscrapers, Parisian-style apartment buildings, a stunning green space twice the size of New York's Central Park and a theme park four times bigger than Disneyland.

Work on the Doha Metro Line in Qatar began in 2016. Built in phases, the three lines were set to open in 2020, and the final line in 2026. However, one of the lines (and its 13 stations) opened to the public early in a soft launch in May 2019. The majority of the network is set to be ready for when the city hosts the 2022 soccer World Cup. The system's four lines are expected to encourage a large shift from cars to trains, helping to alleviate road congestion. The metro will also bring a further economic boost to the country through the development of real estate projects along the route. The cost of building the network has been estimated at Riyals 131.1 billion ($34.9bn/£25.7bn).

The Crossrail project will link the UK's south east to Central London via 60 miles (100km) of railway, as well as making it easier to travel around the capital itself. It is estimated that the new line, called the Elizabeth Line, will be used by 200 million people every year and bring another 1.5 million people within a 45-minute commuting distance of London, which is thought will provide an economic boost of £70 million ($95m) annually. It will also drive the construction of 90,000 new homes along its route. Originally due to open in 2018, the project has been delayed several times and is currently expected to finish in 2022. Due to the delays, Crossrail is already almost £4 billion ($5.4bn) over its original £14.8 billion ($20bn) budget. And the cost is expected to rise further.

On 5 January 2021, the Indian Supreme Court approved a Rs 200 billion ($2.7bn/£2bn) project to redevelop central Delhi, including a vast new parliament building. Despite backlash from critics, who claim the development is essentially a vanity project by Prime Minister Narendra Modi, construction will go ahead on the project, which will see the grand complex of government buildings undergo a transformation. Included in the plans are a triangular parliament building and a new residence for Modi. The project is scheduled to be completed by 15 August 2022, the 74th anniversary of Indian Independence.

A large-scale infrastructure project set to make it possible to travel between San Francisco and Los Angeles in under three hours, the California high-speed rail project, also known as the "bullet train", is predicted to be finished by 2022, although contractors have warned the project is likely to overshoot that deadline. The same goes for the project's budget; originally set to cost $40 billion (£30bn), since then projections have shown that this part of the line will actually cost double that. On 17 December 2020, it was reported that more than 5,000 construction workers had been despatched to work on the project since it began. 

Rising sea levels present an existential threat to Venice. In fact, since the 1500s the sea has risen by an average of half a foot per century. To counter the risk, work began on MOSE, an enormous system of barriers costing $6.1 billion (£5.2bn), back in 2003. However, plagued by corruption and cost overruns, the megaproject, which was meant to have been up and running in 2011, won't actually be finished until 2022 at the earliest.

China is building a wall at the border between its southwestern province of Yunnan and neighbouring Myanmar, Vietnam and Laos. Parts of the wall have already been completed, such as the 4.5-metre (15-feet)-high wall on its border with Vietnam, which was constructed between 2012 and 2016 at a cost of Ұ150 million ($21.8m/£17.7m) according to Chinese state media Xinhua. But now the authorities are expanding the wall to block all 1,300 miles (2,090km) of its southwestern border with Myanmar and beyond, in order to prevent smuggling, trafficking, and the spread of COVID-19. Critics have also suggested the wall is being built to keep Chinese citizens in the country, as historically people have travelled to Myanmar and Vietnam for business and not returned. Despite protests from the Myanmar government, China has pushed forward with the wall's expansion, and the key points of crossing are set to have surveillance cameras. Pictured is part of a temporary gate at the China-Myanmar border. The entire wall project is slated for completion in October 2022.

Construction started on Saudi Arabia's industrial city Jubail II back in 2005 but it's not expected to be finished until 2024, with a further 50,000 residential units to be added by 2026. The city, which is considered by many to be the world's largest industrial engineering project, will consist of at least 100 industrial plants, an 800,000-cubic-metre (28.3 million cubic feet) desalination plant, and an oil refinery producing 350,000 barrels a day, as well as two large ports and a six-lane highway. Located in the city of Jubail, 305 miles (490km) north of capital Riyadh, the development is likely to double the city's size and the engineering works alone are estimated to cost $80 billion (£59bn).

Construction began on the world's largest nuclear fusion project, the International Thermonuclear Reactor (ITER), in Provence, southern France in July 2020 and is expected to be finished in 2025. The €20 billion ($24bn/£17.8bn) project offers clean and unlimited power via nuclear fusion, a process that mimics the reaction's generation in the sun. It's no mean feat though: the reactor will consist of almost 3,000 tonnes of superconducting magnets held together by 124 miles (200km) of cables, with the magnets needing to be cooled to -269°C (-398°F), which is the temperature of interstellar space.

It's been pegged as the world's largest collection of theme parks, but Dubailand in the United Arab Emirates has had its fair share of hiccups along the way. Announced in 2003, the megaproject is divided into six zones: Attractions and Experience World, Sports and Outdoor World, Eco-Tourism World, Themed Leisure and Vacation World, Retail and Entertainment World, and Downtown. The giant amusement park, which is expected to be twice the size of Walt Disney World Resort when completed, was put on hold in 2008 before construction restarted in 2013 and the theme park started to welcome its first guests in October 2016 even though elements of the project, such as Universal Studios Dubailand, are yet to be completed. The $64 billion (£48bn) project is set to be fully finished in 2025.

Jakarta, the capital of Indonesia, is the fastest-sinking city in the world, with parts of it dropping by almost 10 inches (25cm) a year. In an attempt to save the capital, the Great Garuda sea wall is currently under construction with an estimated price tag of $40 billion (£30bn). Construction began in 2014 and is expected to be finished in 2025, with plans including a massive sea wall stretching for 25 miles (40km) across Jakarta Bay which would create a man-made lagoon, around which a new coastal city will be built.

 

The Chuo Shinkansen is a new railway under construction in Japan. The high-speed maglev line will use magnetic levitation to move the train without it touching the ground, and the train from Tokyo to Osaka is expected to be the fastest in the world. Construction began in 2014, with the first stage of the project, between Tokyo and Nagoya, due for completion in 2027. The 178-mile (286km) line had an inital budget of ¥9 trillion ($86.8bn/£63.9bn).

 

Under construction since 1985, Libya's Great Man-Made River Project is a network of underground pipelines which will take water from underground aquifers in the Sahara to the coast. When finished, the project will irrigate more than 350,000 acres of arable land and provide more safe drinking water to Libya's cities. The project is expected to be completed in 2030.

The UK's HS2 was greenlit in February 2020 by Prime Minister Boris Johnson. Europe's largest infrastructure megaproject, the hugely expensive high-speed rail scheme has seen its cost rise several times, and estimates are now at around £106 billion ($143bn), triple its original budget. The first phase, which is due for completion between 2028 and 2031, will link the capital London to the city of Birmingham in the centre of England, and calls for the construction of 140 miles (225km) of lines, a number of new stations and the upgrading of existing terminals.

India's most breathtaking construction megaproject, the $90 billion (£66.5bn) Delhi Mumbai Industrial Corridor will include 24 industrial regions, eight smart cities, two airports, five power projects, two mass rapid transit systems and two logistical hubs. The first phase of the project, a freight corridor linking India's two biggest cities, has been delayed and may not be ready now until 2030, while the final phase is scheduled for completion in 2040.

Despite high levels of pollution in the country, China's biggest environmental threat is lack of water. The Water Diversion Project aims to solve this by transferring 45 billion cubic metres (1.6 trillion cubic feet) of water to the north each year. The project, which began in 2002, is a monumental undertaking that will link China's four main rivers: the Yangtze, Yellow River, Huaihe and Haihe. It will take around 50 years to complete and its budget has already doubled to $69 billion (£57.1bn). The project has faced criticism following the relocation of 330,000 people and concerns about environmental damage.

Rail transportation in the UAE is currently extremely limited. The Etihad Rail Project plans to change this, with 750 miles (1,200km) of track transporting goods, thereby taking vehicles off the road. The first stage of the project was launched in 2016 and has since been completed. The second phase is now also underway although Etihad Rail is not confirming a completion date. Overall the project is set to cost $11 billion (£8.9bn). More widely, it will form part of the Gulf Cooperation Council (GCC) railway network, which will eventually link the UAE to Saudi Arabia, Qatar, Kuwait and Oman. 

Now read about the megaprojects changing cities around the world

Or discover some over-budget and delayed megaprojects