Protected areas are predominantly natural areas established and managed in perpetuity, through legal or customary regimes, primarily to conserve their natural resources. Despite the acute pressures of rapidly increasing human populations, more and more protected areas are still being declared in the Indomalayan Realm. Here, it is worth remembering that the concept of protecting natural areas in tropical Asia is very ancient and may have taken root in the Indian sub-continent, where the practice of affording special protection to patches of forest can be traced back several thousand years to hunter-gatherer societies. The World Conservation Monitoring Centre (WCMC) is gradually expanding its capabilities as an international centre for information on protected areas, which is managed by its Protected Areas Data Unit (PADU). As part of the WCMC core programme, PADU is gradually compiling a series of regional protected areas directories, with priority addressed to tropical countries where much of the world's biological diversity is to be found.