The rock will split, we shall come at the wonder, we shall find the Hesperides
The whole poem is vaguely apocalyptic. The hesperides are the "daughters of evening" and of the west where the sun sets. The splitting rock implies destruction and also creation. The line is two-fold. It can be apocalyptic because the "splitting" which results in basically the symbol of the sunset implies the end of humanity, especially when couched in the first world war period. But it can also imply hope that human tools can help us break this "rock" and maybe reach the beautiful sunset. It is the intertwined nature of hope and destruction, beauty and destruction, and modernity and creation/destruction which make this poem express the great contradiction of the first world war period. But as we know that war was not the end, nor was the next, nor will the next likely be either. There will always be another sunset until there simply isn't. The poem encapsulates the eternal and human here in one piece.