GYONGYOS, a city of Hungary, situated at the foot of the Matra mountains in the county of Heves. Population (193o) 21,281. The Gyongyos river, rising in the Matra mountains, flows by the city and thence south-east to join the Tarna, a subaffluent of the Danube. There are several churches, a large Franciscan college, hospital and gymnasium. Near by is the open air sani torium of Bene.