Integrating environmental education with information and communication technologies (ICT) creates a unique opportunity to better convey to the young public the idea of protecting the environment. Great ease with which today's students use modern computer tools and techniques provokes their interest in participation in the activities in which such tools and techniques are widely employed. Environmental education is most frequently pursued through extracurricular activities that involve direct interactions of students with nature. Environmental Information Centre UNEP/GRID-Warsaw has undertaken and carried out a project with the goal to create a multi-functional Internet portal presenting the assets of the Kampinoski National Park. The content of the portal was developed by the Park staff; it also included data and information materials created by appropriately trained students and tourists while visiting the area. The Virtual Kampinoski National Park portal contains three virtual educational trails charted leading through the Park.s areas of particular interest and along which a number of protected nature objects can be seen. Each trail is described in a short text supplemented by multimedia materials such as 360° panoramic pictures, movies, sound, as well as nature-related thematic maps and special data files that, prior to venturing out, can be downloaded to mobile navigation devices such as GPS units or PDA units equipped with GPS modules. While on an Internet virtual hike, the user may visit a number of virtual educational trail stops with information about those particular places, see movies showing spring and summer vegetation as well as pictures shot in four directions (north, south, east and west). On a real hike, tourists equipped with GPS or PDA units and specially designed data entry questionnaires (available on the portal to download and printout) may make field observations regarding such important topics as alien tree species (their presence indicating disturbed ecological balance in a given habitat), tourism infrastructure (availability, condition), tourism pressure evidenced by stray paths created besides marked trails, and, finally, wildlife observations. In all cases, they can take measurements of geographic location of a given observed phenomenon and later transfer such field-collected data into the electronic data questionnaires available on the portal. The data is then processed by a special application and finally visualized on the portal for other users. The map server has been developed based on two software solutions, namely MapServer and Maps- Google. The former is used to display various thematic maps presenting individual components of the Park's environment, while the latter can be used to conduct virtual trips in the Park and is equipped with a number of additional multimedia features. Thus, the three educational trails are visualized on the portal along with thematic layers showing nature-related information such as vegetation or forest habitats - all against the background of the ortophotomap. Attached to each trail stop are their GPSmeasured geographic coordinates as well as illustrative materials such as pictures showing the stop and its immediate vicinity. Additionally, selected trail stops are presented by means of 360° panoramas (both photographic and movie) and archival pictures - all of them can be displayed in a special media presentation window. The Virtual Kampinoski National Park.-portal has already been put to a good use during field educational classes for school teachers and students, entitled .Navigation in the backpack.. During the classes, the participants pursued a number of educational tasks while hiking on the trails in the Kampinoski National Park. Collected data (results of field observations and measurements, their geographic coordinates, photographic documentation) were then uploaded onto the portal, processed and visualized. The students used modern navigation tools and - as an additional fun-task - they were engaged in a navigation-based field game called geocaching which is about finding .treasure boxes.-hidden in places of given coordinates.-.Navigation in the backpack.-project proved a very attractive supplement to the schools.-regular curriculum, the students could learn how to use GPS tools in the field and how to creatively use Internet.