a natural semi-cave and small water tunnels carved into the water along lake zurich zuerichsee oder zürichsee, wädenswil

amazing ancient background beautiful beauty black blue bright canton carved caves contrast dark ecological environment europe extreme famous flame forest green grieving health hot lake landmark landscape light medieval moss mountain mystical natural nature oder outdoor reflection reflections river rock scenery scenic schweiz semicave small speleology spring stone summer swiss switzerland tourism travel tunnels turquoise underground view waedenswil water zuerich zuerichsee zurich