Understanding the long-term functioning of Australia's tropical savannas is central to the management and conservation of these ecosystems. An environmental history of the Darwin region's mesic savanna is presented from Girraween Lagoon, approx. 25 km southeast of Darwin, where pollen and charcoal analysis of a 5 metre sediment core provides a record spanning the previous 12,700 years. Results show the gradual development of permanent water at the site, surrounded by a dynamic landscape where changing climates and local people's use of fire has shaped the vegetation from that of a savanna to an open forest. [ABSTRACT FROM AUTHOR]