I soon struck the dank lower level and felt again the dampness that denoted my position under the riverbed, but still I could not hear the rush of the water. And indeed I knew that whatever mighty river had rushed roaring to the sea in those ancient times, there was no such body of water among the hills today. I halted, flashing my light about. I was in a vast tunnel, not very high of roof, but broad. Other smaller tunnels branched off from it and I wondered at the network which apparently honeycombed the hills.