The article represents an overview of three proposed protected areas (PAs) in the Leningrad Region. The background data substantiating necessity of those PAs were collected during the research focused on the detection of biologically valuable forests in Podporozhye and Tikhvin Districts. The largest PA «Severo-Svirskiy» consists of three clusters. Predominant aim of this PA is conservation of biologically valuable old-aged taiga forest (including some rare plant communities which are more characteristic of the middle taiga zone), intact oligotrophic bogs, an ecosystem of a large oligotrophic lake, as well as complexes of rare and vulnerable species of vascular plants, mosses, liverworts, lichens and fungi, which are connected with the intact ecosystems. The main aim of «Elm forests of the Oyat River Valley» natural monument is conservation of the northernmost elm forests in the Region composed with with Ulmus glabra, as well as some other forest plant communities of terraced slopes of the Oyat River, which serve a refuge for many species protected in the Leningrad Region. The botanical natural monument «Golomenskiy Mokh» comprises a medium-sized oligotrophic bog with «islands» covered with forest. The main object for conservation there is a stable population of the protected species Epipogium aphyllum, which is related to a well-preserved spruce forest on one of the «islands». In addition, spruce and spruce-aspen forests on the «islands», as well as pine and aspen forests surrounding the main oligotrophic bog, with several more protected species of lichens, fungi, mosses and liverworts have been discovered.