City Under Siege was a map on the first version of Metal Gear Online included in Metal Gear Solid 3: Subsistence. It shows a cityscape. It was later ported onto the second version under the name Urban Ultimatum.
It contained a large office building to the east, a warehouse to the west, the red and secondary buildings to the southwest, the landing and the bank to the south, a grassy area a story to the south below the landing/bank, several crates to the northwest, and an underground tunnel area.
There were two spawn points for the level. One was located at the easternmost top ledge, and the other was near the stairs at the landing and the bank area. The latter also had a crawlspace that led from the spawn point to the grassy area.
Some strategies included camping near flights of stairs to pick enemies off while at the same time protecting the player. This wa especially useful for players who were spawned at spawn point 1. Alternative strategies include using the bank and its columns/trashcan as cover to hep get across and to the other side of the street, especially when the landing is near the respawn point. The player could also use a small ally or sneak down into the grassy area to access the underground tunnel instead of using the main route of taking the stairs. The player likewise could use grenades to flush out any enemies lurking near the stairs.
For players utilizing the Warehouse's rooftops, it's strongly advisable that they mafe it quick and also brought along a cardboard box, as not only could the enemy see the player easily from the adjacent buildings, but the metallic surface on the roof would also result in the player's footstep sounds being amplified.
Players on the buildings could use them to snipe them. The Red Building was smaller than the Office Building, but it had enough architecture to supply a lot of hiding spots. For instance, on the top of the Red Building, the player could use its four pillars as a hiding spot while picking off enemies. It was also likely to snipe other players on the Office Building from behind a small ledge on the roof. The secondary building could also be accessed from the Red Building by flip at the ledge. The secondary building, of all the building rooftops, was the most risky due to its open structure, but it also sometimes spawned a bonus weapon like the RPG-7.
The Gako in Rescue Mission was always on the green box near the office building.