The Divina Commedia, or Divine Comedy, is an epic poem written by Dante Alighieri (c.1265 - 1321). The poem tells of Dante's journey through the three realms of the dead: Hell (Inferno), Purgatory (Purgatorio), and Heaven (Paradiso). The poem is also an allegory of the soul's journey towards God. It is considered to be the greatest literary work in the Italian language.
For a full exploration of the Divine Comedy, check out the ambitious website The World of Dante.