Dante

The Florentine poet Dante's [1265-1321] Divine Comedy, about his journey through the afterlife, his love Beatrice and his favorite ancient writer Virgil is a great and complicated work--all three parts are very distinct. People usually flock to the Byronic, morbid and interesting 'Inferno' [Hell] section. It is indeed terrifying and creepy.

Dante was a famous Italian poet during the Middle Ages, he was one of the first to use Italian instead of Latin, allowing more people to enjoy his work. Be sure to read the funny stories of Boccaccio or the lovely courtly poetry of Petrarca [often written Petrarch in English]; they too wrote in Italian, a major shift in history.

The Paradiso [Heaven] part is not as well read, but there are interesting and eerie passages there too. Here's a snippet from Paradiso Canto XXXI, you can read this part here--and you can read the whole thing here:
[...]
In fashion, as a snow-white rose, lay then
Before my view the saintly multitude,
Which in his own blood Christ espous'd.  Meanwhile
That other host, that soar aloft to gaze
And celebrate his glory, whom they love,
Hover'd around; and, like a troop of bees,
Amid the vernal sweets alighting now,
Now, clustering, where their fragrant labour glows,
Flew downward to the mighty flow'r, or rose
From the redundant petals, streaming back
Unto the steadfast dwelling of their joy.
Faces had they of flame, and wings of gold;
The rest was whiter than the driven snow.
[...]