Martha Cooper, © National Geographic Society

Underground Sepphoris. A triumph of Roman engineering, the reservoir for Sepphoris measures 541 feet long and about 22 feet high at the end seen in the photo. Carved from a natural cavity in the limestone bedrock, it lies about a mile east of Sepphoris’ acropolis. A surface aqueduct brought water to the reservoir from the springs of Abel, three miles away, but archaeologists have not yet discovered the tunnel that took the water from the reservoir into the city. Built in the early first century to supply water for Herod Antipas’ city, the reservoir continued in use until the fifth century.