The archaeological site of Kymi on Viglatouri hill, three kilometres from the shore, comprises a settlement of the prehistoric and Geometric periods, with its houses, temples, squares, streets, and graves. The visible remains, which cover the entire hill, belong to the Geometric settlement, whose total extent has not yet been established.

The architectural remains include rectangular and apsed buildings, roads paved with small rocks, pebbles, and pottery sherds, and a small section of the city wall at the foot of the hill. At the centre of the settlement was a square with an oval stone-built building, a heroon-shrine according to the excavator, which was unlooted and yielded considerable quantities of pottery finds of the mid-eighth century BC. The shrine's apse was the first structure discovered during the 1984 excavations. Similar oval buildings of the Geometric period are found elsewhere in Euboea - for example at Lefkandi, where religious celebrations in honour of the dead took place - but also at Smyrna and Areion. The presence of an adjoining stone-paved area, built over Early Geometric graves, supports the theory that the oval building was a shrine. East of this area was a cist containing animal bones, probably a kind of sacrificial hearth similar to those known from the East and the Cyclades. The shrine, which flourished from the mid-eighth century BC and was destroyed around 700 BC, is believed to have served for the worship of noble citizens, who travelled at sea and were lost.

Beneath the remains of the Geometric settlement are those of earlier occupation phases, which go back to the Neolithic period. The pottery kilns of the Middle Helladic period and the so-called megaron of the Mycenaean period, located under the later shrine-heroon, are especially noteworthy.