In "Ozymandias," what does the alliteration in the last three lines of the poem signify or mean?
Here are the last three lines of the poem:
Nothing beside remains. Round the decay
Of that colossal wreck, boundless and bare,
The lone and level sands stretch far away.
The alliteration in the first line here (remains/Round) serves to unite the line musically although the first part of it ends in a period. Perhaps the poet wanted "Nothing beside remains." to stand alone for thematic emphasis, but he did not want the line to sound divided and choppy. The alliteration seems to be more about sound than theme.
In the next line, "boundless and bare" alliterate with the effect of emphasizing the vastness and desolation of the desert surrounding the statue of Ozymandias. This vastness contrasts the smallness of what was once no doubt considered to be a great structure.
Finally, in the third line, "lone" alliterates with "level" and "sands" alliterates with "stretch." Again, the alliteration contributes to the image of the desert, but with an added element. The sands stretch "far away." The words "far away" are suggestive of time as well as place. Time continued long after the arrogant Ozymandias lived and ruled and died and was forgotten, his broken image buried beneath desert sands. His mighty works were no match for eternity.