The water-harvesting system of the ancient Sassi di Matera, in the Basilicata region of southern Italy, represents a clever way of living with water in an arid climate. The terrain, with its soft rocks (Calcarenite di Gravina), provided the foundation for the water-harvesting system that shaped the cave dwellings of Sassi physically, socially and culturally. People caught, guided and stored water in private and public spaces, mostly underground, ensuring its availability for all. In 1993 UNESCO declared the cave village a World Heritage Site. Unfortunately, the water-harvesting system of Sassi di Matera is no longer functioning. Its historic ingenuity is not as visible as the system deserves and its cultural and social values are almost forgotten. Using layered visual analysis – the illustrative method – knowledge can be collected and communicated in drawings to get insight regarding more resilient, circular, and people-related approaches (Bobbink, Chourairi and Di Nicola 2022). This article and the included drawings focus on the water system’s value, from which we can learn today.