St Lucia is the world’s oldest protected estuary and Africa’s largest estuarine system. It is also the centerpiece of South Africa’s first UNESCO World Heritage Site, the iSimangaliso Wetland Park, and has been a Ramsar Wetland of International Importance since 1986. Knowledge of its biodiversity, geological origins, hydrology, hydrodynamics and the long history of management is unique in the world. However, the impact of global change has culminated in unprecedented challenges for the conservation and management of the St Lucia system, leading to the recent initiation of a project in support of its rehabilitation and long-term sustainability. This timely volume provides a unique source of information on the functioning and management of the estuary for researchers, students and environmental managers. The insights and experiences described build on over 60 years of study and management at the site and will serve as a valuable model for similar estuaries around the world.