When it comes to Adelaide, South Australia, population and steets are important questions for residents. These stats can help you determine the growth of the city. There are over four million people living in Adelaide. However, it's important to remember that these statistics do not include the surrounding suburbs. The city is actually separated from the surrounding metropolitan area by a ring of public parklands. Its central business district (CBD) is defined by a small cluster of high-rise buildings centered on King William Street, which runs north-south through the city center. The area around the CBD is largely comprised of medium to low-density apartments, townhouses, and detached houses.