Modern GIS (Web-Geographic Information System) technologies have significant applications for earth sciences. One example is the Internet Atlas of Karst. A karst area of high-mountain character was selected. The Internet Atlas of Karst was prepared using map server and spatial database applications. The applied technologies made possible numerous extended functions, enabling transfer of data into maps, viewing the maps, accessing description attributes, conducting geometrical analyses and many other functions. The Atlas of Karst may be extended into other karst areas, as well as other analytical functions, and may serve as a portal to create a comprehensive karst information system.