[h=2]1.) International Space Station (ISS): $157 B[/h] The worlds most expensive object ever constructed is the ISS or International Space Station of Canada, European Space Agency, Japan, Russia and the United States. It is still under construction and is expected to be completed by 2011. This space station serves as a research laboratory that has a microgravity environment. It is by far. [h=2]2) Itapu Dam Brazil/Paraguay: $27 B[/h] The worlds most expensive dam is the Itapu Dam situated Between Brazil and Paraguay. This hydroelectric river dam which was completed in 1984 costs $27 billion. This mega project spans the Parana River located on the border between Paraguay and Brazil. 3.) Three Gorges Dam China: $25 B One of the worlds most expensive dams is the $25 billion Three Gorges Dam in China. This mega project is expected to be completed year 2011. This hydroelectric dam, which is the largest electricity-generating plant of any kind in the world, spans the Yangtze River in Sandouping, Hubei, China. As a consequence in building the dam, many archaeological and cultural sites were flooded and about 1.3 million people were displaced. 4.) James Bay Project Canada: $13.8 B This Canadian project is worth $13.8 billion. James Bay Project is the phase 1 of a hydroelectric river dam which was completed in 1972. These series of hydroelectric power stations are located on the La Grande River in Quebec, Canada. It is one of the worlds largest hydroelectric systems with a generating capacity of 16,000 megawatts 5.) CVN-78 Class Aircraft Carrier USA: $8.1 B The CVN_78 Class Aircraft Carrier is a US Navy supercarrier under construction with an estimated cost of $8.1 billion. It is expected to be finished in 2015. The first hull of the line will be named Gerard R. Ford. It is intended to replace the current Nimitz-Class Carriers. New technology such as the Electromagnetic Aircraft Launch System and other designs will be implemented. [h=2]6.) Alaska Pipeline USA: $8 B[/h] Alaska Pipeline is a mega project of the United States which was completed in 1977. This $8 billion oil pipeline is also known as the Trans-Alaska Pipeline System (TAPS). This very expensive project includes the Trans-Alaska Pipeline, 11 pump stations, several hundred miles of feeder pipelines and the Valdez Marine Terminal. It is also commonly called the Trans-Alaska Pipeline or Alyeska Pipeline. The pipeline has already shipped almost 16 billion barrels of oil since its operation up to present. 7.) Olkiluoto Nuclear Power Plant Finland: $7.2 B The Olkiluoto Nuclear Power Plant in Finland is worth $7.2 billion. This power plant is expected to be completed in 2013. It is located on Olkiluoto Island on the shore of the Gulf of Bothnia. This nuclear power plant consists of two BWRs with 860 MWe each 8.) ITER - International Thermonuclear Experimental Reactor: $6.5 B ITER is an experimental fusion reactor expected to be finished in 2016. This $6.5 billion project by the European Union, India, Japan, China, Russia, South Korea and the United States is an international tokamak (magnetic confinement fusion) research/engineering project that could help to make the transition from today's studies of plasma physics to future electricity-producing fusion power plants. [h=2]9.) Alcochete Airport Portugal: $4.5 B[/h] Alcochete Airport in Portugal which is expected to be completed in 2017 has an estimated cost of $4.5 billion. It is located in the countrys capital Lisbon. Construction of the said airport will probably start early 2011. [h=2]10.) Mir Russia: $4.3 B[/h] It is a space station launched in 1996 which cost $4.3 billion. The name Mir means peace or world. This very expensive object was the largest artificial satellite.