The web is 106 square meters in size and was created by an unusual collaboration between two spider species, reports the Belgian news agency Belga .
"The colony consists of an estimated 69,000 individuals of Tegenaria domestica (common house spider) and more than 42,000 of Prinerigone vagans (from the orb weaver spider family)," writes the research team that studied the web in an article in the scientific journal Subterranean Biology.
The cave system, with an entrance in Greece and the deepest parts in Albania, is located on a tributary of the Vjosa River, which flows into the Adriatic Sea.
