The Phoenician island-city of Motya, off the west coast of Sicily, has long been a focus of archaeological research. Earlier excavations identified a large rectangular basin interpreted, by analogy with Carthage, as a ‘kothon’ or artificial inner harbour. Recent investigations of this feature, however, lead the author to a new interpretation. Rather than a harbour, the so-called ‘Kothon’ is revealed as a sacred freshwater pool at the centre of a monumental circular sanctuary hosting three large temples. The pool, watched over by a statue of Ba'al, also served as a surface for observing and mapping the movement of stars, as emphasised by the alignment of structures and features positioned around the sacred enclosure.