Beneath the turquoise waters of Lake Ohrid, the "Pearl of the Balkans", scientists have uncovered what may be one of Europe's earliest sedentary communities, and are trying to solve the mystery of why it sheltered behind a fortress of defensive spikes.
A stretch of the Albanian shore of the lake once hosted a settlement of stilt houses some 8,000 years ago, archaeologists believe, making it the oldest lakeside village in Europe discovered to date.
Radiocarbon dating from the site puts it at between 6000 and 5800 BC.