even the oldest setlement know çatak huyuk in turkey there where a few and their entrance as by the roof but then again i meant 6 store buildings not just 2 store high buildings (actually the 1st i´ve heard was in a poeni setlement in sicily not even in carthage but i can assume the building constructions where similar )

brave sir robin i think thats the story about jericho and the "spy" moved on to the house of a jew already living inside the walled city

the bible speaks of a 6 meter high wall (or 9 can´t recall atm) but then again it might be extremly exagerated but thats just a personal opinion

resume: 6 story high buildings carthage had
according to what i read from diferent authors it mantained a 600.000 population and towards the ends it was able to recruit a 80.000 population militia for it´s defence before the final fall at the end of the 3rd punic war (i hate this definition it wasn´t a true war the carthies never had a chance even if they had won and had maintaned their freedom they would only have been invaded and sieged again without much of a chance to strike back)