Starożyn preserve is located in the center of Augustów Primeval Forest within Płaska forest district in Gmina Płaska. It was made to protect the virgin forests of Augustów Primeval Forest. Forests of this preserve are mostly oak-hornbeam, mixed or alder. This section of the forest is highly diverse and its vegeta cover is very rich. There are a lot of under protection species of plants here, such as: arnica montana, martagon, early-purple orchid, orchis militaris or bearberry.