'Laang Heck' means the long hedge.
'Laang' is Luxembourgish for long, and a 'Heck' is a hedge or bush. On the Luxembourg City Tourist Office’s 1999 city map, 'Laangheck' is the Luxembourgish name of the Rue des Aubépines (aubépine is French for hawthorn), the street on the east side of Merl cemetery.