Płock

Płock is a seat of the county (powiat) in the west of the Masovian Voivodeship. From 1079 to 1138 it was the capital of Poland. The Cathedral Hill (Wzgórze Tumskie), along with Płock Castle and the Catholic Cathedral containing the sarcophagi of some Polish monarchs, is listed as a Historic Monument of Poland. It was the main city and administrative center of Mazovia in the Middle Ages before the rise of Warsaw, and later it remained a royal city of Poland. It is the cultural, academic, scientific, administrative and transportation center of the west and north Masovian region. Płock is the seat of the Roman Catholic Diocese of Płock, one of the oldest dioceses in the country, founded in the 11th century, and it is also the global headquarters for the Mariavite Church. Poland's oldest school and largest oil refinery are located in Płock.