Marketplace And St. Gangolf Church In Trier, Germany. The Construction Of St. Gangolf Church Begun At The Turn Of The 15Th Century Although A Four-Storey Tower Had Already Been Built A Century Earlier. The Tower's Later Top Two Storeys Were Donated By The Widow Of The Lord Mayor, Adelheid Of Besselich. St. Gangolf Church Was The City's Market Church That Rivalled The Trier Cathedral.