The sudden surge of the Río Mundo Curiosity · Riópar, Sierra del Segura, Albacete Phenomenon that occurs at the source of the río Mundo, very close to Riópar (Albacete), within the Calares del Río Mundo y de la Sima Natural Park, one of the five natural parks of Castilla-La Mancha. It consists of the sudden release of a large quantity of water, an uncommon occurrence found only in very few caves of karstic origin. During periods of heavy rain or after the melting of snow accumulated in winter, the Chorros spring expels far more water than its aquifer has received, forming spectacular waterfalls -true explosions of water and light known locally as "el reventón"- a phenomenon caused by the action of normal and inverse siphons inside the karst. Photo: Wikipedia / Wikimedia Commons (CC BY-SA) What to see and do in Riópar