why is the land rent so high in CBD?

Answer 1

If doing business in CBD is more attractive than elsewhere for reasons of easier access to qualified workforce as well as to customers, then the companies are prepared to pay more rent than elsewhere.

As more a company can earn at a specific place, as more is left over to pay the rent - and of course there is a competition, so at the end only those companies stay in CBD who really can profit of the area.

Answer 2

Supply and Demand