The island of Gla, an enigmatic Mycenaean citadel in the north-eastern corner of the Copais basin lies 70 miles north of Athens, in the region of Boeotia. Lake Copais was the largest lake in Greece until the late-19th century CE when it was drained to create land for cultivation. As the waters receded, however, the unexpected remains of ancient ditches and embankments emerged. Traversing the width of the Copais basin, they provided tantalising evidence for an earlier drainage project, one dating to the last phase of the Greek Bronze Age around 1300 BCE. The discovery prompted archaeologists to re-appraise the mightiest but least known fortress of the Mycenaean civilization in Greece.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/1679/the-island-of-gla-a-mycenaean-mystery-solved/.