 
Jerusalem's water supply was quite complex with the Solomon's pools as
 its hart (between the nrs 50 and 51): two supplying aqueducts 'el Biyar'
 (46 -50) and 'Arrub (1-18), two channels towards Jerusalem, te lower
 one (30 - 45) and the higher one (55 - 59), and a branch line towards
 the Roman desert fort Herodion (60 -67).