Groundwater plays a significant role in sustaining Doñana's ecosystems, particularly wetland hydroperiods. However, several threats to groundwater quantity and quality (e.g., climate change, pumping) have contributed to Doñana's hydrological degradation over the past decades. This talk will deal with groundwater dynamics in Doñana, trying to shed some light on what are the main characteristics of the aquifer, how much water goes in and out, whether pumping is affecting wetland-groundwater interactions or not, and how could water management be improved.