An aerial view of a model of Jerusalem as it appeared in the First Century, A.D. [or C.E.]. Note that this was the urban portion and that there were "suburbs" that ringed the city as well. The large structure to the right is, of course, the Temple.
Population in the First Century was about 50,000 within the walls and, according the Tacitus, around 600,000 if the surrounding area is added to the total. [I had always been told 300,000, but there is no sure way of knowing, of course. The 50,000 figure is based on an anthropologist's estimate of how many could fit within the walls without succumbing to famine and/or disease from a fouled water supply.]