Echternach (ĕkhˈtərnäkhˌ) [key], town (1991 pop. 4,211), E Grand Duchy of Luxembourg, on the Sûre (Sauer) River, at the western border of Germany. It manufactures plastics and is an agricultural, industrial, and tourist center, with mineral springs that have been frequented since Roman times. Of note in Echternach are the Church of St. Peter and St. Paul (11th cent.), part of the Benedictine abbey (founded c.700) where St. Willibrord is buried, and the town hall (16th cent.). A colorful pilgrimage and procession is held annually on Whit-Tuesday.