Base

Bases are a property for building and maintaining ground units. Not all of them are belong to us.

In-depth
Cities give three terrain stars.

They can be used to build and repair ground units, generate income (usually 1000 G per day) and provide terrain cover.

In Advance Wars 2: Black Hole Rising, Lash's ground units get a 30% attack boost on bases. This is reduced to 15% in Advance Wars: Dual Strike. Kindle's ground and air units in Advance Wars: Dual Strike get a 40% attack boost while on bases.

In Days of Ruin, bases provide a hiding place for ground units, and can only be revealed either when an enemy unit moves past the city or if they're in the vision range of one of Lin's ground units when she uses her CO Power.