The Sostro District (Slovene: Četrtna skupnost Sostro) or simply Sostro is a district of the City Municipality of Ljubljana, the capital of Slovenia. It is the largest district of the capital and is located in the eastern part of Ljubljana. It is named after the formerly independent settlement of Sostro. The Sostro area is extensively forested and for this reason it is sometimes styled the "green lungs of Ljubljana." Historically, the wood from these forests was used for building houses, stables, and beehives, and as a basis for various crafts. Even nowadays, local people gather berries, mushrooms, and chestnuts here and sell them at the Ljubljana market.