They were really onto something with the aesthetics of this level. It's something I wish they had played on a bit more. Frankly, I wouldn't have complained if the entire game was just levels that looked like this.
>big grassy valleys filled with forlorne stone structures left behind by an extinct alien race
>the gentle humming of wind and birds as you explore
>all of these subtle blues, greens, greys and purples set against a majestic skybox
>the forerunner structures occasionally spouting off some odd energy beam, as if trying to send a message to another structure on the opposite side of the ring, to a recipient that no longer exists
To me, this is Halo. It was this blend of familiar yet unfamiliar, earthly yet alien, natural yet high tech. What a beautiful level.