megastructure
extremely large artificial object
Dyson sphere
hypothetical megastructure, originally described by Freeman Dyson
Intercontinental and transoceanic fixed links
persistent, unbroken road or rail connection across water that uses some combination of bridges, tunnels, and causeways and does not involve intermittent connections such as drawbridges or ferries
artificial world
megastructure in the fields of science speculation and fiction
Alderson disk
hypothetical artificial astronomical megastructure
stellar engine
theoretical megastructure