The Hoddle Grid is the contemporary name given to the approximately 1.61-by-0.80-kilometre (1.00 mi × 0.50 mi) grid of streets that form the Melbourne central business district, Australia. Bounded by Flinders Street, Spring Street, La Trobe Street, and Spencer Street, it lies at an angle to the rest of the Melbourne suburban grid, and so is easily recognisable. It is named after the surveyor Robert Hoddle, who marked it out in 1837 (to Lonsdale Street, extended to La Trobe Street the next year), based on the city grid established in the first survey of Melbourne conducted by Robert Russell (architect) in 1836, establishing the first formal town plan. This grid of streets, laid out when there were only a few hundred settlers, became the nucleus for what is now Melbourne, a city of over five million people.