(A) Wall lamination (northern segment of tunnel) shows alternating silty and muddy layers. The dominant waterline level is at about 1.5 meters above the tunnel floor. (B) Speleothems extending from dripstone on the tunnel ceiling. The innermost (oldest) laminae, dated to the fourth century B.C.E, cover eighth-century-B.C.E plaster and ancient waterlines such as seen in (A).