- "City in the desert. Classic street to street firefights."
- — In-game description
Invasion is similar to the map Crash in Call of Duty 4: Modern Warfare, featuring many elevated positions, close range fighting, and cover. Invasion is actually based off the area that Pelayo crashes in "Shock and Awe" in Call of Duty 4: Modern Warfare. On the eastern side of the map, the street is exactly the same as the one that Jackson walked down to retrieve Pelayo from the helicopter.
Invasion is an excellent map for car bombing other players, as C4 can be hidden under the many Humvees on the bridge and in the city. There are a total of nine Humvees but only seven can be blown up as the two near the left side of the base are invincible. On Search and Destroy game modes players can immediately shoot at the enemy spawn with grenade launchers. This is especially devastating on hardcore.
Invasion was also a planned multiplayer map in Call of Duty 4: Modern Warfare Variety map pack. All that is known to prove its existence in Call of Duty 4 are two files called "loadscreen_mp_invasion.iwi" and "compass_map_mp_invasion.iwi" present in the game's source files.
- There is a shop full of dummies.
- The player can find posters of Khaled Al-Asad in some of the streets.
- The cab seen at the beginning spawn point of the OpFor has the initials "IW", another one of Infinity Ward's hidden references.
- In most streets, newspaper articles with a picture of the nuclear bomb that killed Jackson and his squad in Call of Duty 4 can be found.
- The building directly ahead from the gas station has a large glass window that the player can break. However the blinds prevent the player from going through easily.
- Under the map on spectate there is a destroyed Russian jeep from Call of Duty 4 just across the bridge along with some tanks.
- The Taxis at the OpFor spawn have advertisements for a hamburger called the "Tuesday Special".
- Standing still anywhere on the map, playing in either a private match or solo, the player can hear someone speaking in the background. It seems to be mostly gibberish.
- The Rent-a-Johns in the army outpost has the name "Porter Potty," and the number on them is 1-800-555-DUMP.
- In Modern Warfare (2019), the map is reimagined as Euphrates Bridge. Invasion is found in the out-of-bounds region of the map with the exact location with respect to the bridge.