The waterproof rock in the interior of the mountain "Grebenzen" reveals the origin spring of Pöllau.
The Pöllau origin spring bubbles almost stronger than the spring in Zeutschach. The geology of the Grebenzen leads to this unique appearance. An almost 600m high water-permeable limestone layer sits on a base of phyllites. This waterproof rock forms a threshold in the interior of the mountain, thus revealing the springs.
The origin spring Pöllau can be visited all year round.