The WDPA Consortium : 2004 world database on Protected areas
Contains a geographic information system (GIS) databse. ESRI's ArcExplorer is a free viewer provided by the Environmental Systems Research Institue (ESRI) that allows viewing digital geographic data, do simple manipulations and queries (scale, map overlays, color rendering, explore attribute data, etc.). Project files are provided for ArcExplorer 2 and 4, ArcGIS and ArchView