Another pervasive symbol throughout The Inferno is the binary of light and dark. Hell is, of course, associated with darkness. Dante often remarks on the darkness of hell and how some areas of hell are completely devoid of light. God and heaven, on the other hand, are associated with light. (There is some light in hell, but it is generally not the result of God's brightness, but rather of burning fires that cause pain and suffering.) The first thing that Dante notices when he finally exits hell is the sight of the stars in the sky, which he could not see underground, symbolizing that he has returned from the dark world of sin. But beyond its associations with evil, darkness can also represent a kind of uncertainty, since one cannot see clearly in the dark. In the eighth circle of hell, for example, Dante first thinks the giants are towers, because his sight is impaired by the darkness. Thus, when the poem opens in a dark forest, this does not necessarily mean that Dante is in a place of sin (though it may also carry this association), but especially means that Dante is in an uncertain, unknown place. He is in a state of mental confusion matched by his inability to see clearly in the forest. He tries to climb the mountain in the beginning of the poem because he sees the light of the sun shining over it, promising some kind of knowledge or clarity. However, as Virgil informs him, he must come to the light through a more difficult path, one full of darkness.