Dive into the pool

Not trusting the darkness of the three tunnels you decide that the water would be your best bet, after all you could definitely go for a bath if nothing else. Slowly you submerge yourself into the cold water and you quickly feel your clothes becoming completely soaked. Once you're all the way in you open your eyes and see mostly darkness. The glow of your pendant helps you figure out that beneath the opening of the pool the area clearly expands out quite a bit, however the glow is not bright enough to show you how large the room is and as you look around you can't manage to find any walls but you do see something shiny reflecting the light deeper into the water.