Leonardo drew the hills north of Florence on folio 20v of Madrid Ms. II, indicating Monte Ceceri, Fiesole and Monte Morello. The latter rises to a height of over 900 metres above sea level, beyond the Mugnone; from its slopes springs the Terzolle stream, mentioned by Leonardo on folio 23r of the same Madrid Manuscript.
Fiesole, an ancient Etruscan and Roman city situated 295 metres above sea level, is mentioned in the "Codex on the flight of birds" and in Ms. G by Leonardo, who had also purchased here two plots of farmland with a stone quarry near the Oratory of Sant’Apollinare.
Monte Ceceri (414 metres above sea level) is recalled by Leonardo in the "Codex on the flight of birds" in relation to his prophecy on human flight: «The great bird will take its first flight from the back of Monte Cecero, filling the universe with stupor, filling all writings with its fame and bringing glory to the nest in which it was born». Legend has it that the flight attempted by Zoroastro, taking off from this hill, ended in a disastrous fall.