Between the 7th and 6th centuries BC, the Etruscans must have discovered and used the easy ford of the Arno River at the confluence where the plain was also narrower due to the proximity of the hills to the north and south. At that point they had probably built a footbridge or a ferry service, which must have been located about ten meters from the current Ponte Vecchio in Florence, in the narrowest ford. The Etruscans, however, preferred not to found cities on the plain for defense reasons (from foreign armies and floods) and settled about six kilometers from the ford on a hill, where the fortified center of Vipsul, today’s Fiesole, was born.