The river too was liable to flood, as it still is, and a familiar ode of Horace tells us how in the time of Augustus the water reached even to the heart of the city.[9] Lastly, the site has never really been a healthy one, especially during the months of July and August,[10] which are the most deadly throughout the basin of the Mediterranean.

Pestilences were common at Rome in her early history, and have left their mark in the calendar of her religious festivals; for example, the Apolline games were instituted during the Hannibalic war as the result of a pestilence, and fixed for the unhealthy month of July.

Foreigners from the north of Europe have always been liable to fever at Rome; invaders from the north have never been able to withstand the climate for long; in the Middle Ages one German army after another melted away under her walls, and left her mysteriously victorious.
There are some signs that the Romans themselves had occasional misgivings about the excellence of their site.

There was a tradition, that after the burning of the city by the Gauls, it was proposed that the people should desert the site and migrate to Veii, the conquered Etruscan city to the north, and that it needed all the eloquence of Camillus to dissuade them.

It has given Livy[11] the opportunity of putting into the orator's mouth a splendid encomium on the city and its site; but no such story could well have found a place in Roman annals if the Capitol had been as deeply set in the hearts of the people as was the Acropolis in the hearts of the Athenians.