Gla was an important fortified site of the Mycenaean civilization, located in Boeotia, mainland Greece. Despite its impressive size, more than ten times larger than contemporary Athens or Tiryns, Gla is not mentioned in the Iliad.
The site is located on a limestone outcrop or hill that jutted into Lake Kopais (now drained) or formed an island within it. The flat-topped outcrop rises up to 38m above the surrounding area. It measures circa 900 x 575m (at the widest point). The ancient name of the site is unknown, it is unclear whether it is one of the Boeotian places named by Homer (some scholars suggest that Gla is Homer's Arne).