Data on protected areas can be combined with other data to create additional information. Estonian use case demonstrates how officials in municipalities get benefits and aid to decision making procedures from information about number of protected areas in one municipality and how area of a protected are is divided between different municipalities. In addition officials can easily locate a protected area and obtain detailed information about the specific area by using chained systems. It means that Estonian use case uses URL-linking to Estonian Nature Information System and further on to Estonian Land Board web mapping service. Following data is used in the use case: protected areas in Estonia (National parks, Nature Conservation Areas, Landscape Protection Areas) – altogether 366 map objects protected nature monuments : trees (single trees, tree groups), stones (boulders, stone fields), springs, waterfalls, rapids, caves (sandstone, karst caves), exposures (limestone cliffs, terraces, limestone exposures, stratotypes), karst phenomena (swallow holes) – altogether 1048 map objects. As background data a map layer with municipalities’ (241) borders was used. Use case is implemented with OGC compliant free ware: MapServer 4.2 on server side (WMS) and MapLab 2.2 on client side. Data has also been registered at Nature GIS Thematic portal.