What factors would make a place a CBD (Central business district)? ?

Question

What factors would make a place a CBD (Central business district)?

eg. It must be is a reasonably highly populated area, and must be at a location where many trade routes are.

What else? (Please mention as many as you can)

Answer 1

Major landmarks, a big cluster of shops and eating areas, and streets being closed off for malls are some of the things I would consider characteristics of a CBD area.

I live in Sydney, Australia and our CBD has all of the above, and so much more. I've lived here my whole life, and while some people find the city too fast, I've felt myself thrive on it's liveliness. I feel like a part of the human race when I walk along George Street.

You see people in such different states of existence and there is a sense of excitement in some way, even when nothing spectacular is happening.