The nearly thousand-year-old Catholic parish church of St. Martin is the oldest landmark of St. Goarshausen-Wellmich. The church is located directly at the foot of the castle mountain below Burg Maus. The Catholic parish church is a construction made of slate quarry stone with occasional inserts of Taunus quartzite. It is recorded that in the year 1042 there was still a monastery inhabited by monks around the church.