Light commenced his survey for Adelaide on 11 January 1837 at the North West corner of his central grid, now the intersection of North and West Terrace. Of the 1042 town acres that he surveyed 700 make up the central city grid (originally called South Adelaide, but now known as the central business district) and the other 342 are in North Adelaide.
Each of the lots were numbered in sequence, starting at this corner, known as Town Acre 1. The original lots were one acre square, although most have now been subdivided into smaller parcels. However, it is still generally possible to see the outline of the original grid, particularly in the major streets that dissect the grid.
Light was instructed to look at examples from colonial settlements in North America for his plan. Philadelphia (established in 1687) Charleston (1672) and Savannah (1733) in the United States offered models of grid patterns, broken by central squares, and in the case of Savannah, surrounded by a belt of parklands. The Canadian city of Toronto was planned in a similar way, but the plan was not realised.
Light’s plan included six squares, five in South Adelaide and one in North Adelaide, all of which remain today, although some have been altered. The main city grid has four major roads defining its boundaries, North Terrace, East Terrace, South Terrace and West Terrace. Eleven streets cross the grid East- West and six cross it North to South. The names of the original streets were determined at a meeting on 23 May 1837.
Rights to purchase the original town acre lots had been sold though pre-sales in England and were selected by ballot once Light’s plan was finalised but the majority were sold at auction in Adelaide, fetching between £2 and £14 each. Light purchased 13 lots himself in both North and South Adelaide.
In 1929, a bronze tablet to commemorate Light’s survey was mounted on a granite boulder on the northern side of North Terrace, where the new Royal Adelaide Hospital stands. The entrance to the Newmarket Hotel opposite, built in 1883, stands on the original top corner of the very first lot, Town Acre 1.