In the late fifteenth century, Antonio di Tuccio Manetti (1423-1497) was the first in a long series of commentators to study the location, shape, and dimensions of Dante’s Hell. In his reconstruction, the vast abyss of the damned was aligned on the city of Jerusalem, and its entrance was situated near Cuma and Lake Avernus. The huge underground cavity stretched from Sicily to Persia, and from Ethiopia to the Caspian Sea. Manetti determined its widest opening on the Earth’s surface by plotting a circle with a radius of 1,700 miles on a nautical map.
Place yourself in front of the nautical map, and, taking the compass, place one of its arms over Jerusalem, and extend the other arm out to one thousand seven hundred miles [...] and you will see that [...] the first place on dry land that touches the moving arm of the said compass will be in Italy, around Cuma [...]Dialogo di Antonio Manetti… circa al sito, forma, et misure de lo inferno di Dante, Florence 1506, fol. 55v.