The Tamina valley with the impressive Tamina gorge was shaped by an arm of the Rhine glacier, which had advanced over the Kunkelspass, and the Sardona glacier. The origin of the Pfäfers thermal water remains a mystery. Scientists assume that the water seeps into the Tödi area (Canton Glarus) or the Sardona area, penetrates about 1,000 meters deep into the earth, is heated in the process and reaches the surface again in the Tamina Gorge through transverse rock fissures after 10 ½ years.
A few meters away from the Old Bath Pfäfers is the entrance to the mystical thermal water source gorge. The 450-meter-long, safe and also somewhat adventurous path leads along the rock, in the last section via a tunnel into the rock interior, past the thermal water fountain to the spring water grotto.