"Sunstone" is not only Paz's most famous poem, the one that to some extent earned him the Nobel Prize. In the literature of his language, its position has been considered analogous to that of Eliot's "The Waste Land" in the canon of Anglo-American literature. Some of the most essential features "of the new literary avant-garde in Latin America and Spain," writes Pere Gimferrer, "can only be correctly interpreted if we take into account the existence of Sunstone."
[...]
The great power of the poem lies in the fusion of metrical and automatic writing. That is, in the intersection of Paz's associative, often surreal, imagery with a strict verse, which in the metrical tradition of Spanish has been associated with works of a particularly narrative character. With the difference that Sunstone is not a narrative poem, but a lyrical and contemplative one - an ontological song that, without ever ceasing to be an entirely personal discourse, sometimes rises to the sphere of pure thought.
The Greek reader who has in mind the lyrical poetry of ideas represented by "The Free Besieged" or "The Palm Tree" understands what I mean.

From the Translator's Introduction