To me, it looks like a bigger version of Narrows with some differences.
You already posted this and I moved it to Community Creations where it belongs: https://www.halowaypoint.com/en-us/forums/92b5c5cfee994e7299608301a6b2eb11/topics/guess-what-map-this-is-based-on-%5E_%5E-perview-wip/448c4e99-0b21-4535-a5af-ca48b7571ccb/posts