Miercurea Ciuc (Romanian pronunciation: [ˈmjerkure̯a t͡ʃjuk];  listen, Hungarian: Csíkszereda, Hungarian pronunciation: [ˈtʃiːksɛrɛdɒ]; German: Szeklerburg) is the county seat of Harghita County, Romania. It lies in the Székely Land, an ethno-cultural region in eastern Transylvania, and is situated in the Olt River valley.