Karst topography is a geological formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite, but also in gypsum. It has also been documented for weathering-resistant rocks, such as quartzite, given the right conditions. This is an incomplete list of the major karst landscape areas of the world.
The protected areas network of Madagascar is managed by the Madagascar National Parks Association (PNM-ANGAP). The network includes three types of protected areas: Strict Nature Reserves (IUCN category Ia), National Parks (IUCN category II) and Wildlife Reserves (IUCN category IV). At the 2003 IUCN World Parks Congress in Durban, the Malagasy President, Marc Ravalomanana, announced a bold initiative to more than triple the area under protection from approximately 17,000 km² to over 60,000 km² (from 3% to 10% of Madagascar's area). This "Durban Vision", as it has been dubbed, involves broadening the definition of protected areas in the country and legislation has been passed to allow the creation of four new categories of protected area: Natural Parks (IUCN category II), Natural Monuments (IUCN category III), Protected Landscapes (IUCN category V), and Natural Resource Reserves (IUCN category VI). As well as allowing these new objectives for protected areas management, the new legislation also provides for entities other than PNM-ANGAP to manage protected areas. Other governmental agencies such as the forestry and fisheries departments now manage some sites in addition to PNM-ANGAP. It is planned that private and community-run parks and reserves will also be created within the next few years. In December 2005, the first extra 10,000 km² of the new Protected Areas System of Madagascar were granted protection status.