At http://popular-archaeology.com/issue/summer-2016/article/the-ancient-wor… …. a hill, 118m high, on the coast of Aghios Prokopios on the island of Naxos (in the Cyclades) has outcroppings of chert that have attracted humans for thousands of years – from deep in the Palaeolithic into relatively modern times. Today the hill is situated on a promontory that juts into the Aegean Sea. During the Ice Age and early Holocene Naxos was part of a much larger land mass, a big island comprising several of the Cyclades plus low lying areas that are now on the sea floor. The hill was probaly a long way from the coast at that time. The attraction was the easily worked chert seams – hence the so called workshop (cert debitage).
Meanwhile, at http://archaeologyinbulgaria.com/2016/07/12/thracian-shrine-with-newly-d… … stone altar and rock tomb date back between 1200 and 900BC (shortly after the end of the LB age).