Cut Halo 4 levels
From Halopedia, the Halo wiki
During the development of Halo 4, a number of maps were concepted and partially-developed though cut from the game for various reasons. Many of these maps were concepted by company Digital Extremes, contracted by 343 Industries to help with the production of the game's DLC map packs. A number of map ideas and concepts were pitched to 343 but went unused, and have since been released online.
An original map design developed by Certain Affinity and referred to as "Dish" can be found in the tags build. The map takes the form of a long canyon, with multiple levels. The map is complete with vehicle and turret spawns, alongside respawn points for players - though appears not to have progressed beyond the early blockout stages. Interestingly, this map contains spawn points for the Revenant design which was intended to appear in the game. The relatively late cutting of the Revenant from the game indicates that Dish may have been in development relatively late in Halo 4's development cycle.
Known only in the files of the Halo 4 tags build as
Other cut levels
Covenant underwater technology
Identified in a series of concept art uploads all titled
Last Resort remake
One map concept shown involves a paintover of the sniper tower area of the Halo 3 map Last Resort. Its filename,
Other DLC map concepts
Some callout sheets for individual map props have been posted online, of which tie to no particular known map.
Development and testing levels
Lighting reference test maps
First referred to as such in the Halo: Reach Legendary Edition developer commentary by Martin O'Donnell, the so-called "Stripey Room" or
VFX test map
This map was created by 343 Industries to test out visual effects such as the disintegration on Promethean weaponry.