Strabo, Geography

Above the city of the Chalcidians is situated the Lelantine Plain. In this plain are fountains of hot water suited to the cure of diseases, which were used by Cornelius Sulla, the Roman commander. And in this plain was also a remarkable mine which contained copper and iron together, a thing which is not reported as occurring elsewhere; now, however, both metals have given out, as in the case of the silver mines at Athens. The whole of Euboea is much subject to earthquakes, but particularly the part near the strait, which is also subject to blasts through subterranean passages, as are Boeotia and other places which I have already described rather at length.¹ And it is said that the city which bore the same name as the island was swallowed up by reason of a disturbance of this kind. This city is also mentioned by Aeschylus in his Glaucus Pontius:“Euboeïs, about the bending shore of Zeus Cenaeus, near the very tomb of wretched Lichas.
”²In Aetolia, also, there is a place called by the same name Chalcis:“and Chalcis near the sea, and rocky Calydon,
”³and in the present Eleian country:“and they went past Cruni and rocky Chalcis,
”⁴that is, Telemachus and his companions, when they were on their way back from Nestor's to their homeland.