'Kierch' is Luxembourgish for church: Hamm’s Holy Cross Church.
Its choir dates from the first half of the 14th century and is first mentioned in 1337. From the 17th century a miraculous cross drew pilgrims to Hamm, until the French Revolution. Hamm became a parish of its own in 1867, and in 1902 the church was enlarged with a nave. Gothic frescoes found under later paint in 1966 were restored, most recently in 2020.