The ruins of the old town of Pyli and its castle can be found on a hilltop, 3-4 kilometers away from the modern village of Pyli, approximately 17 kilometers from the city of Kos.
The old town is an abandoned settlement on the foot of a Byzantine castle, built in the times of Macedonian dynasty (9th century A.D. - 11th century A.D.). When the knights of Saint john took hold of the island in the 14th century, they enforced the fortifications on the casstle in order to improve the area's defensive capacities.
From the castle the visitor will enjoy magnifficent views of the nearby islands of Pserimos and Kalymnos and of the shores of Asia Minor.
The old town itself has been called "the Mystras of the Dodekanese", implying the importance of its medieval archaeological monuments such as its byzantine churches. Of particular importance is the 14th century church of Ypapanti (Candlemas), with its beautiful frescoes, a wonderful wood carved altar piece and columns from an older temple of the vicinity. Another church worth visiting is the temple of the Archangels (church of the Taxiarche).
It should also be noted that that the founder of the monastery of Patmos saint Christodoulos originally founded a monastery here in Pyli, the monastery of the Castriani, the Catholicon of which is still preserved today as the Flevariotisa church.