How did Dante portray purgatory in the Purgatorio?

In his Purgatorio, Dante Alighieri portrays purgatory as a seven-story mountain located at the antipodes of Jerusalem, serving as a realm of spiritual rehabilitation and the poem's true moral starting point. Unlike the involuntary alienation found in the Inferno, the Purgatorio depicts life as a pilgrimage where penitents actively work toward their purification.123

The structure of this realm corresponds to the seven deadly sins, with each of the seven terraces dedicated to purging a specific class of sin. Dante presents this environment as a place of spiritual dawn, where historical, political, and moral vistas are explored, and where poetry and the arts are celebrated.31

As the pilgrim Dante ascends, he transitions from being an observer to an active participant, eventually subduing his own personality to progress. The journey concludes at the summit in the earthly paradise, where his guide Virgil—representing human reason—must depart, making way for Beatrice to lead him toward divine mysteries. Through this vision, Dante created a poetic synthesis of theology, Ptolemaic cosmology, and moral psychology to depict the gradual restoration of the soul’s likeness to God.132