OLSZTYN, POLAND—The First News reports that a large cave and a network of tunnels have been discovered in the limestone crags underneath Castle Olsztyn, which was built in the fourteenth century in southern Poland. Archaeologist Mikołaj Urbanowski and his colleagues were investigating what is known as the Lower Castle Cave, where they recovered a medieval tile depicting a falconer, when they realized its floor surface was made of hardened sediment. “The initial results are very promising and indicate the existence of a network of voids and crevices under the floor of the already known cave,” explained Adrian Marciszak of Wrocław University. The study suggests the cave is about 23 feet deep. For more on Polish archaeology, go to "Off the Grid: Krakow, Poland."