One of the most important discoveries was a rock-cut tunnel leading down through the heart of the rock to a spring in a cave 94 feet below the surface of the rock and 120 feet below the level of the present surface of the ground.[50] This was to enable the people of the city to obtain water in time of siege. It was used for some 500 years and was apparently closed up about 1300-1200 B. C. Its beginnings go back accordingly to the first Semitic period. A palace of the Maccabæan time, apparently built by Simon the Maccabee, 143-135 B. C., was also discovered.[51] (Cf. 1 Macc. 14:34.) Various walls were discovered, which at different times encircled the city. The most massive of these was apparently constructed during the eighteenth Egyptian dynasty, and continued to be the city wall down to the Babylonian Exile. At some time after its construction towers had been inserted in the wall. These towers were shown to be a later insertion by the fact that their stones touched the stones of the wall on each side, but were not interlocked with them. Mr. Macalister thinks that these towers may have been inserted by Solomon when he fortified the city (1 Kings 9:15-19). At some later time the weakness of such a tower had become apparent, and a bastion had been built around it.[52] The excavation at Gezer was fruitful in many directions. Other aspects of it will be taken up in future chapters in connection with other topics. (10) _Beth-shemesh._--The next task undertaken by the Palestine Exploration Fund was the exploration of Ain Shems, the Biblical Beth-shemesh. (See Josh. 15:10; 2 Kings 14:8-14, etc.) Ain Shems, like Gezer, is situated in what was in Biblical times the Shephelah. It is near the station of Der Aban on the railway from Jaffa to Jerusalem. Excavations were carried on at this point in 1911 and 1912 under the direction of Dr. Duncan Mackenzie, who had had ten years’ experience on the staff of Sir Arthur Evans, the explorer of Crete. At the bottom of the mound the remains of a very early settlement were discovered.[53] Above this the ruins of a once prosperous city, which was for that time large, were found. It was surrounded by strong walls and one of its rugged gates was discovered on the south. In the upper strata of this city imitations of Cretan pottery were found. As it is probable that the Philistines came from Crete, or were intimately associated with people who were under Cretan influence, this pottery is doubtless Philistine. The city which was encircled by this wall had passed through two periods of history. The original wall was built before the domination of Palestine by Egypt. As this domination began about 1500 B. C., the earlier fortress of Beth-shemesh belongs to that period. The second period belongs in its earlier strata to the age of the El-Amarna letters, in which the city is called Beth-Ninib. The upper period of it belongs, as has been noted, to the Philistine period.