Kyustendil is one of the most ancient Bulgarian towns. In the V-IV century BC Thracians founded a settlement, attracted by the healing mineral springs. In the I century AD Romans made the town an important castle, trade route and popular balneological resort they called Pautalia. In the I-II century Pautalia grew bigger and became the administrative, economic and cultural center of the surrounding territory. Its important role continued throughout the late Antiquity as well.