Infrastructure connects the world, and sometimes there are projects of unimaginable sizes. Here is a list of the top 5 infrastructure projects that have been built and others under construction.

Water transfer project from south to north - China

Time to build: 15 years - Work is under way
Cost: more than $ 80 billion

North of China where nearly 50% of the country's population lives. However, the region has only 20% of the total water resources available in China. The project is moving water from the largest rivers in southern China to the north through three channels of 600 miles (965.6 km). The central canal was completed in 2014, but the eastern and western routes remain.

When completed, the project will carry 44.8 billion cubic meters of fresh water annually, equivalent to 18 million Olympic swimming pools.

Hong Kong Bridge - Zhuhai - Macau

Time to build: 8 years
Cost: $ 10.6 billion

The bridge is about 50 km long and runs through two industrial islands and is one of the largest road infrastructure projects in the world. The project began in 2009 and is expected to end in December of this year.

The project was proposed in 1983, and a major effort was made before reaching its current status. After opening it will connect Hong Kong and the Western Pearl River, and it will shorten the Hong Kong-Macao four-hour journey to just thirty minutes.

Great Industrial River Project - Libya

Time to build: 35 years - under construction
Cost: $ 25 billion

The largest irrigation project in the entire world is located under the Sahara in Libya. About 2,816 km of pipes extend across the region and connect 1,300 wells with an average depth of 500 meters. This project will provide 6.5 million cubic meters of fresh water throughout the country daily.

It has been in operation since 1985, and when it is completed it will irrigate 350,000 acres of desert land. The bulk of the project's funding came from the Kadhafi government, while much of it has already been completed, but it is due to end in 2030.

Highway system in the United States

Time to build: 25 to 60 years
Cost: $ 511 billion

The idea of ​​this project came from political Dwight Eisenhower, which is thousands of kilometers of highways. It aims to improve shipping and transportation throughout the country.

Construction began in 1956 by turning old roads into highways. The last of which was completed in 1992 and is the largest infrastructure project in the world.

Songdo International Business Area - South Korea

Time to build: about 6 years
Cost: more than $ 40 billion

This area was built on reclaimed land in the ocean off Seoul. 1500 acres of land, the largest human projects have been reclaimed. It was completed in 2015 and now has 800,000 residential apartments, covering 50 million square feet of office space and 10 million square feet of retail space.

70% of the project was funded by an American real estate company, and the remaining stake went to the South Korean company Bosco.