Lost Forest.
Lost Forest was a map that appeared in the first version of Metal Gear Online included in Metal Gear Solid 3: Subsistence. The Lost Forest was a stretch of forest that acted as a maze. The forest was split into five sections, with the north being the deepest part of the forest, a meadow in the center, cliffs to the east and west, as well as the only building in the area: a depot, to the south.