High Ground

High Ground is a multiplayer level in Halo 3. It is an old UNSC base in New Mombasa that was reactivated after the Slipspace cataclysm that destroyed Mombasa. One of the few asymmetric maps in the game, High Ground is great for One-Sided objective games such as One-Bomb, One-Flag, and Territories.

Layout
"High Ground" is an asymmetric map featuring an elevated, but crumbling, UNSC base surrounded by cliffs on 3 sides and a beachfront on the fourth. There are multiple ways to approach and enter the base; through the main gate that must be activated (only in asymmetric gametypes, otherwise it is open by default), or side passages which offer more protection and discretion.

Beach
Attacking players spawn at the far side of the map, aptly named "the beach". If the main gate is open, it can be used as a quick entrance or escape from the base.

A variety of weaponry and equipment has been placed near the beach, and outside the base walls to aid attackers in storming the base. Perhaps the two most valuable weapons include the Sniper Rifle and the M41 Rocket Launcher, and the shotgun but this can be reached by the players who spawn in the base by using vehicles, so in most games a battle over control of the Rockets (and sometimes Camo) ensues at the start of the game and accordingly with the power weapons' respawn rates. Players can also find a Portable Gravity Lift, Bubble Shield, and Overshield to aid in their attack. In addition to the weapons and equipment, players can choose from a Mongoose or Ghost to get to the base wall faster.

Fortress
This large, but crumbling base is where defending players spawn. In the back of the base, to the left, players can find a large mortar or a SAM (Surface-to-Air-Missile) site; it is unusable and is merely a piece of scenery for the level. Several vehicles spawn in the back of the base, allowing defenders to quickly catch fleeing attackers, or for attackers to make a quick getaway. These vehicles are a Ghost and 2 Mongooses. A broken down control room is located in the centre of the base, complete with computers and a radio set. This control room is the objective area for CTF and Assault gametypes, in which attackers must steal the flag, or arm the bomb in this room. It is also possible to jump above the control room by first jumping on the crumbling wall, then to the top. This position offers no protection though, and a good sniper can take you down from the beach. To the far left of the base is the "Pipe Room," where attackers can enter the base via a small pipe that connects to the front of the base.

The right of the base is mostly indoors, and offers 2 levels of play. The lower-most level can be accessed several ways; by attackers coming through the bunker or multiple entry points from above or ground level by the base defenders. 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, just as the gate in Zanzibar or Last Resort would be. 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 line of site to incoming attackers. It also leaves them open to Battle Rifle or Sniper fire from the beach as well. The Spartan Laser can be found on the tower on the right side of the base wall. This tower is somewhat vulnerable however, as there are some fusion coils stacked on one side of it. In addition, a Machine Gun Turret is mounted above the main gate. The Rocket Launcher can be accessed by defenders as well, if they quickly rush up and over the base wall, beating the attackers.

Strategies

 * There is a hatch on top of the bunker that can be blown open by shooting or jumping on the lock for quick entry.
 * A good place to hide is behind the Laser Tower; there is a small opening in the wall where there is a stone ledge where players can simply jump over and camp there with the laser, sniper, or rocket launcher.
 * A popular trick is to use the portable grav lift to get onto the laser tower.
 * The portable grav lift can be used to drive vehicles and jump people over the gatehouse.
 * In SWAT the defending team should take control of the sniper tower. It is a good position to see the entire field of play. Duck every so often as to not provide opponents with easy headshots.
 * On the beach, there are several trees one can jump on hide among the branches. Several of these overlook the base and other parts of the map, so this is a pretty good sniper position. The one problem is that you cannot see the ground under you very well, but the advantage to this is your opponents have the same view of you, so it's generally easy to go unnoticed.
 * For Team SWAT in that tunnel where the Grav Lift is a rock you can hide behind and kill people from because many people walk through that tunnel and you get a good view of the beach.
 * If someone is in the tower with the Spartan Laser, and you have a Rocket Launcher, if you fire with good aim your rocket can destroy the fusion coils and kill the person with the laser.
 * On top of the tower where the laser spawn (Laser Tower) there is a ceiling made of some sort of fence. This place is accessible by either crouch jumping from the wall through a large hole in the ceiling, which can be quite difficult. Or by placing a grav-lift on top of the bridge and then launching towards the roof. This can be a good sniper-spot.
 * On Shotty-Snipers, it is sometimes a good idea to wait in the middle of the pipe with your sniper out and watch you radar. When you see someone coming close to you, then snipe him or her, as they will most likely have their shotgun out.
 * Using the Machine Gun Turret on the gate wall while it's mounted is not a good idea because you are very vulnerable to Sniper or Battle Rifle fire. Instead, rip off the turret and walk with it among the base.

Forge

 * Adding Fusion Coils around major walkways allows for easier kills, this will also change the pace of the game, as people will then try to avoid the places with the Fusion Coils.
 * Opening the door and placing an item where the door will close will cause them to be open on that map variant from the beginning. This will be more useful for free-for-all than the launch version.
 * If you leave the map and walk out to sea you will get a killed by the guardians.
 * You can easily get out of the map by using the High Ground Vacation glitch.

Trivia

 * High Ground was originally thought to be the successor to Zanzibar until Bungie revealed Last Resort. However, due to its general appearance, namely the beachhead assault layout, it has several familiarities to Zanzibar. The layout of the map is such that defenders spawn in the war-torn base, with attackers spawning on the beach.
 * In a way it is like the World War Two D-Day landings in Normandy, due to the fact the attacker start at a beach and the defending base has a more firepower.
 * During the Halo 3 Beta pictures of Cortana appears for brief seconds on all the computers placed on the map. The face appears on every computer at the same time.
 * Cortana's face appears every 117 seconds.
 * "Red vs. Blue" as well as "This Spartan Life" held "transition" episodes on this map, or at least made a reference to the map. These references are used in order to make a smooth transition from Halo 2 to Halo 3.
 * The radio inside the fort where the flag spawns transmits three different Morse Code messages. When translated they are "frogblast the ventcore" a reference to Bungie's classic FPS Marathon, "sababwl" an acronym found on the Halo Soundtrack which was a quote from Bungie's Martin back when the original Halo was about to be released, the acronym stands for "shiny and bumpy and bursting with love!" and "Don't make us kick your ass" a classic Bungie saying.
 * The Radio inside the fort where the flag spawns also transmits a musical piece from Halo: Combat Evolved, entitled "Under Cover of Night".
 * There are small fish that can be seen and killed and will wash up on the shore. The beachfront appears to be leading out into the ocean, but if you manage to get past the barriers you can see land a few miles away, hinting that this might be a wide river or a large lake.
 * It is possible to go deep into the water on this map by overloading it with Trip Mines then sticking a respawn point out side. Or by using teleporters and having one player go through the sender and the other holds the receiver.  If one player does not hold the receiver it will fly back into the map or disappear.
 * Based on the scenery in the distance (specifically the radio antennae that can be seen on the hill across the water), this map appears to be in the same general area as Standoff and Voi; they are both located in Africa.
 * In the piles of trash, there is a paper crane.
 * It is likely that the base was under the control of NATO, as several NATO symbols can be seen throughout the map.
 * On some of the computers in the Control Centre, there are readouts of Pelican Dropships.
 * High Ground has more Covenant Carbine spawn points than any other Halo 3 maps.
 * High Ground is also known as Outpost C9.
 * In a Red vs Blue Halo 3 special where red team was looking into a new map, Church gave High Ground as an option. He said that there was a forty-car garage. The large garage is located at the very back of the base.
 * As stated by Chris Carney in the Bungie Multiplayer Vidoc, there were originally going to be several towers with machine gun turrets being manned by AI gunners. These artificial intelligences would be very biased of the defending team that they would shoot at whatever came up the hill.
 * High Ground appears to be some form of a 'Storm the House' style map.
 * In the Computer Room, you can hear a song from the Halo Soundtrack on the radio, but this is very rare.
 * In Red vs Blue: Reconstruction, Church is based here and left when Agent Washington and Caboose ask him to come with him to the ship that Tex, Sheila and Andy used in Red vs Blue Season 5 when Washington mentioned Tex's name to him.
 * High Ground, as to date, is one of the most hated maps in Halo 3. This is because, of the numerous Mauler spawn points around the map and during matches, players will always wield or dual-wield Maulers and camp at a particular spot, getting cheap kills. And also, each Mauler spawn point has 10 shells in it.