. . . that faire field of Enna . . .

There's something about the Persephone myth that brings out an intense response from later poets, especially Dante, who imaged his Matilda in the garden of Eden as an eternally inviolate Proserpina, and of course Milton in Paradise Lost IV:

Not that faire field
Of Enna, where Proserpin gathering flours
Her self a fairer Floure by gloomie Dis [ 270 ]
Was gatherd, which cost Ceres all that pain
To seek her through the world;

Shelley took some pains to render Dante's lines from Purgatorio 32:

A solitary woman! and she went _40
Singing and gathering flower after flower,
With which her way was painted and besprent.
'Bright lady, who, if looks had ever power
To bear true witness of the heart within,
Dost bask under the beams of love, come lower _45
Towards this bank. I prithee let me win
This much of thee, to come, that I may hear
Thy song: like Proserpine, in Enna's glen,
Thou seemest to my fancy, singing here
And gathering flowers, as that fair maiden when _50
She lost the Spring, and Ceres her, more dear.

Ovid may have seen Enna and the Lake that he says opened to allow Dis's chariot, bearing Ceres' daughter, access to the Underworld. Enna had been an essentially impregnable fortress from ancient times, due to its unusual situation:

Enna is situated near the center of the island; whence the Roman writer Cicero called it Mediterranea maxime, reporting that it was within a day's journey of the nearest point on all the three coasts. The peculiar situation of Enna is described by several ancient authors, and is indeed one of the most remarkable in Sicily. The ancient city was placed on the level summit of a gigantic hill, so lofty as almost to deserve to be called a mountain, and surrounded on all sides with precipitous cliffs almost wholly inaccessible, except in a very few spots which are easily defended, abundantly supplied with water which gushes from the face of the rocks on all sides, and having a fine plain or table land of about 5 km in circumference on the summit, it forms one of the most remarkable natural fortresses in the world.

Wikipedia goes on to say of Enna:

In historical times it became renowned in Sicily and Italy for the cult of the goddess Demeter (the Roman Ceres), whose grove in the neighborhood was known as the umbilicus Siciliae ("The navel of Sicily"); the origin of the toponym Henna remains obscure.

Ovid's Lake "Pergus," where spring was forever until it wasn't, was near Enna:

The neighborhood of Enna is celebrated in mythological story as the place whence Proserpine was carried off by Pluto.[1] The exact spot assigned by local tradition as the scene of this event was a small lake surrounded by lofty and precipitous hills, about 8 km from Enna, the meadows on the banks of which abounded in flowers, while a cavern or grotto hard by was shown as that from which the infernal king suddenly emerged. This lake is called "Pergus" by Ovid [2] and Claudian,[3]