Editing Megastructure (section)

==Proposed==
* [[Atlantropa]], a [[hydroelectric dam]] to be built across the [[Strait of Gibraltar]], lowering the surface of the [[Mediterranean Sea]] by as much as 200 meters.
* [[Trans-Global Highway]], highway systems that would link all six of the inhabited continents on Earth. The highway would network new and existing bridges and tunnels, not only improving ground transportation but also potentially offering a conduit for utility pipelines.
* [[Cloud Nine (tensegrity sphere)|Cloud nine]] is Buckminster Fuller's proposal for a [[tensegrity]] sphere a mile in radius which would be large enough so that it would float in the sky if heated by only one degree above ambient temperature, creating habitats for mini cities of thousands of people in each "Cloud Nine". Fuller also proposed a marine analog consisting of a hollow terraced floating [[tetrahedron]] of reinforced concrete measuring one mile from vertex to vertex supporting a population of one million living in air-deployed residential modules on the exterior with the requisite infrastructure providing utilities (water, power, sewerage, etc.) inside. The modules would have standardized utility ports so as to be completely livable within minutes of arrival, and could be subsequently detached and moved to other such cities.
* [[The Line, Saudi Arabia|The Line]], a 170-kilometer-long [[linear settlement]] in [[Saudi Arabia]], a [[smart city]] currently in the early stages of construction.