The Great Wall of China, at 6,352 km or 3,947 mi long, is a megastructure. This picture was taken near Beijing in February 2005.

A megastructure is a very large artificial object, although the limits of precisely how large vary considerably. Some apply the term to any especially large or tall building.[1][2] Some sources define a megastructure as an enormous self-supporting artificial construct. The products of megascale engineering or astroengineering are megastructures.

Most megastructure designs could not be constructed with today's level of industrial technology. This makes their design examples of speculative (or exploratory) engineering. Those that could be constructed easily qualify as megaprojects.

Megastructures are also an architectural concept popularized in the 1960s where a city could be encased in a single building, or a relatively small number of buildings interconnected. Such arcology concepts are popular in science fiction. Megastructures often play a part in the plot or setting of science fiction movies and books, such as Rendezvous with Rama by Arthur C. Clarke.

In 1968, Ralph Wilcoxen defined a megastructure as any structural framework into which rooms, houses, or other small buildings can later be installed, uninstalled, and replaced; and which is capable of "unlimited" extension. This type of framework allows the structure to adapt to the individual wishes of its residents, even as those wishes change with time.[3]

Other sources define a megastructure as "any development in which residential densities are able to support services and facilities essential for the development to become a self-contained community".[4]

Many architects have designed such megastructures. Some of the more notable such architects and architectural groups include the Metabolist Movement, Archigram, Cedric Price, Frei Otto, Constant Nieuwenhuys, Yona Friedman, and Buckminster Fuller.[5]


There are structures that may be considered megastructures, such as

Networks of roads or railways, and collections of buildings (cities and associated suburbs), are usually not considered megastructures, despite frequently qualifying based on size. However, an ecumenopolis might qualify.



A number of theoretical structures have been proposed which may be considered megastructures.

Stellar scale

A cut-away diagram of an idealized Dyson shell—a variant on Dyson's original concept—1 AU in radius.

Most stellar scale megastructure proposals are designs to make use of the energy from a sun-like star while possibly still providing gravity or other attributes that would make it attractive for an advanced civilization.

Related structures which might not be classified as individual stellar megastructures, but occur on a similar scale:

Planetary scale

Orbital structures

Trans-orbital structures

One concept for the space elevator has it tethered to a mobile seagoing platform.

Main article: Non-rocket spacelaunch


A number of structures have appeared in fiction which may be considered megastructures.

Stellar scale

Planetary and orbital scale

Star Wars (1977 – present, American sci-fi franchise)

Stellaris (2016 video game)

See also


  1. ^ ""about the Megastructure"". Archived from the original on 7 October 2008. Retrieved 16 September 2008.
  2. ^ "The Modern Urban Landscape" by E. C. Relph
  3. ^ Paine, Anthony (2021). "Mega structure". Architectural Review, The – via indexarticles.
  4. ^ "Future Forms and Design for Sustainable Cities" by Michael Jenks, Nicola Dempsey 2005
  5. ^ "Megastructure reloaded: megastructure"
  6. ^ Damian Zimmerman, ICE Case Studies: The Great Wall of China, December 1997
  7. ^, FACTS & FIGURES, Ifugao province Archived 2012-11-13 at the Wayback Machine
  8. ^ "Shell Worlds – An Approach To Terraforming Moons, Small Planets and Plutoids", K. L. Roy; R. G. Kennedy III; D. E. Fields, 2009, JBIS, 62, 32-38
  9. ^ Dani Eder
  10. ^ "Ederworld Analyzed (Concentric Gravity Balloons to Maximize Volume)". Gravitational Space Balloons. 11 December 2013. Retrieved 30 June 2020 – via
  11. ^ O'Neill, Gerard K. (1977). The High Frontier: Human Colonies in Space. William Morrow and Company. ISBN 0-688-03133-1.
  12. ^ McKendree, Thomas Lawrence (9–11 November 1995). Implications of Molecular Nanotechnology Technical Performance Parameters on Previously Defined Space System Architectures. The Fourth Foresight Conference on Molecular Nanotechnology. Palo Alto, California.
  13. ^ Cole, Dandridge M.; Cox, Donald W. (1964). Islands in Space: The Challenge of the Planetoids. Philadelphia: Chilton Book Co. ASIN B0007DZSR0.
  14. ^ Niven, Larry (1974). "Bigger Than Worlds". A Hole in Space. New York: Ballantine Books. pp. 111–126. ASIN B002B1MS6U.
  15. ^ "Tether Transport From LEO To The Lunar Surface" Archived 2011-05-17 at the Wayback Machine, Robert L. Forward, 1991, 27th Joint Propulsion Conference, AIAA 91-2322