Wading deeper into tunnels
In pursuit of the slurping sound I waded onward down the watery tunnel. The water was about 5 feet deep, clear and greenish tinged. Remarkably the floor was composed of pea gravel – tiny little rocks worn smooth and translucent by the running water. I wondered where the pebbles had come from – I am in a dolostone terrain and some of those pebbles were igneous in origin.