Its name derives from s’ega ‘e riu, meaning the ‘marshy river valley’, or from segau de s’arriu, meaning ‘cut in two by the river’, because of the town’s location in a valley crossed by two tributaries of Flumini Mannu. Segariu is a town of 1200 inhabitants close to the border between the Marmilla and Trexenta historical regions with characteristics of both: the rolling hills covered pine groves and Mediterranean shrubs of Marmilla, and the rugged hills interspersed with cultivated, fertile, flat stretches of Trexenta. The town is known for traditional kaolinite and limestone shaping, with clay bricks and roof tiles being produced. In the centre of town, the Museum of Clay, a testimony to the importance of this tradition, is dedicated to salvaging this craft, which has defined the town for centuries.