The practice of dividing up the territory surrounding a new Roman colony to match the city's grid plan of square blocks, normally 2,330 feet (710 m) on a side. The centuriation process was done for land distribution to the settlers and also for inventory. Signs of it were first detected in northern Africa from the 1830s, through surviving crop marks and roads, and have been found, mainly through air photography, in Trier and Homs (Syria) and large areas of northern Italy and Tunisia.