Joseph S. Last identified two aqueducts that transported water to the city from two perennial springs: one near Sotira (the smaller source) 11 km distant and Souni (the larger source) at 20 km distant. The western aqueduct from Sotira was made of an estimated 30,000 terra-cotta pipes 0.20 m in diameter and 0.20–0.50 m long. A trunk line of this aqueducts supplied water to the Sanctuary of Apollo. The eastern aqueduct from Souni consisted of an estimated 60,000 pipes with a 0.30 m diameter and 0.30 m length. Last concluded that the eastern aqueduct was a later addition to supplement the western aqueduct.