From Halopedia, the Halo wiki
High Ground is located around Outpost C9, a former-NATO military base in Voi, Africa, designed to combat "earlier and simpler enemies" than those later faced by the UNSC in the 26th Century. The base was reactivated after the New Mombasa Slipspace Event in October 2552. The base was utilised by the UNSC to test captured examples of the Type-25 Spiker recovered from fallen Jiralhanae in the wake of the Great Schism.
Due to the old NATO architecture and newer UNSC technology, the facility has a mix of crumbling bulwarks and high-tech military equipment. The base has a concrete bunker and large partitioning wall to divide the beachhead and base itself, with a single large blast gate overlooked by an AIE-486H machine gun. A single watchtower is above the bunker, while the other side of the wall has decayed due to time. The back of the base has a small courtyard with an ASRGAM-10X Surface-to-air missile launcher.
High Ground is an asymmetric map featuring an elevated, crumbling, UNSC base positioned along a beach. Low, eroded cliffs lie to the north, east, and west of the base, with the beach lying south of the base. There are multiple ways to approach and enter the base; through the main gate (that is closed only in asymmetric gametypes), or through side passages, which offer more protection and discretion. As one of the few asymmetric maps in the game, High Ground is great for one-sided objective games such as Single Bomb|One Bomb, One Flag, and Territories.
Attacking players spawn at the south side of the map, aptly named "the beach". If the main gate is open, it can be used as a quick entrance to or exit from the base.
A variety of weaponry and equipment has been placed near the beach to aid attackers in storming the base. Perhaps the two most valuable weapons are the sniper rifle and the rocket launcher, though the latter can be reached by the base defenders if they use vehicles. In most games, a battle for control of the rocket launcher ensues at the start of the game, and repeats whenever the weapon respawns. Players can also find a shotgun, gravity lift, bubble shield, active camo, and overshield to aid in their attack. In addition to the weapons and equipment, players can choose between a Mongoose or Ghost to get to the base wall faster.
This large, crumbling base on the northern side of the map is where defending players spawn. In the back of the base, there is an unusable surface-to-air missile launcher. Several vehicles, including Mongooses and a Ghost, spawn just east of the launcher, allowing defenders to quickly catch fleeing attackers, or for attackers to make a quick getaway.
A broken down control room is located in the center of the base, complete with computers and a radio set. This control room is the objective area for CTF and Assault gametypes, containing the flag spawn point and bomb plant point, respectively. Farther east is the "Pipe Room", where attackers can enter the base via a small pipe that connects to the front of the base.
The western half of the base is mostly indoors, and offers two levels of play. The lower level connects the base to a pillbox bunker lying just outside the base's walls; the level also has multiple entry points inside the base. The upper level is used as a choke point to keep attackers from reaching the gate controls on the catwalk. If a player is able to access the gate controls, the base wall gate will be permanently opened, as is the case with the gates in Zanzibar and Last Resort. The base is designed to promote dual wielding, and as such, a number of dual-wieldable weaponry can be found behind the base wall.
The base wall is an important area for defenders, as it gives them a view of most of the beach. Defenders on the wall, however, are vulnerable to battle rifle and sniper rifle fire from the beach. The wall acts as a bridge, connecting the base's eastern side to its western side. On the western edge of the wall, there is a tower where a Spartan Laser and two fusion coils spawn. In addition, a machine gun turret is mounted above the main gate, which is useful for beating back approaching rushes and vehicles. The rocket launcher can be accessed by defenders as well, if they quickly rush up and over the base wall, beating the attackers.