national park «Hvalynsky» Structure and Features of Functioning «GIS-national park» (on an Example of «GIS‑national Park “Hvalynsky”») Authors: Danilov V. A. In article the specialised geoinformation system created by the author «GIS-national park “Hvalynsky”» is considered. Conceptual bases of the GIS, the maintenance of separate modular blocks, thematic structure of databases are shown.