‘Catchment’ is the word by which Tim Robinson designates a unit of the Earth’s surface bounded by higher edges and within which springs, rainfall and smaller tributaries converge, in most cases flowing onward to an outlet that joins it to a more broadly encompassing drainage. Every point on the Earth’s surface is mapped in such a way by elevation and the movement of water. In Listening to the Wind, the first volume of his Connemara trilogy, Robinson further characterises a catchment as ‘an open, self-renewing system, supporting and supported by a vast number of life-forms and all their interrelations’. Across the seasons and over the decades, Robinson has walked the catchments near his home in Connemara. In this essay John Elder argues that not only has Robinson come to know the catchments in intimate detail, but he has also tracked their confluence with the geology, language and history of western Ireland.