Sentence:  To the east and west were the <WSD>"akhets</WSD>", or horizons — liminal zones in which the sun god and the dead king were prepared, either for rebirth into the upper world on the east or for successful entry into the other world on the west, the place of death and burial. 
Meaning of the word marked with <WSD> tags:  the region in the sky in which the sun tarries just before it rises or after it sets