A grid plan is the first basic plan in urban planning. It was developed in ancient Greece.It is a type of city plan in which streets run at right angles to each other, forming a grid. In ancient Rome a grid plan method of land measurement was called a centuriation.
- Michael Gagarin; Elaine Fantham, The Oxford Encyclopedia of Ancient Greece and Rome, Vol. 5 (Oxford: Oxford University Press, 2010), p. 154
- "Colonia Iulia Flavia Augusta Corinthiensis, AD 70s (Reign of Vespasian)". David Gilman Romano and the Corinth Computer Project. Retrieved 6 April 2015.