In science, the $23 billion space station, $4 billion superconducting supercollider and the $3 billion human genome projects are marginally justifiable scientific projects but best understood as monuments to USA capacity. Politicians in Latin America, Africa and Asia have built ill-sited dams and power stations; massive steel plants for agricultural countries; and multi-lane roads to nowhere. Germany mistakenly built a petrochemical plant on its North Sea coast. The UK has an international airport on a distant shore of Scotland. The Philippines has an unworkable nuclear power station sited near three geological faults.
The Concorde supersonic aircraft is a classic example. Capable of propelling 100 passengers paying $3,600 (one way) in a cramped seat from London to New York at twice the speed of sound, whilst consuming more fuel than any other commercial aircraft. In the 1960s the development costs were nearly $5 billion. The aircraft (of which only 7 were produced, rather than the 150 planned) had to be given to the operators. In 1990 a study is being undertaken to produce a new version.
In 1995 the Walloon government (Belgium) decided to complete the construction of the Strépy ship lift -- a project begun in the late 1960s as part of a plan to revitalize the canal trade. The mega-project was abandoned in a state of partial completion, but the government has calculated that the cost of completing the project is cheaper than maintaining the unfinished structure.