Coordinates: 49°40′8.26″N 6°8′33.83″E / 49.6689611°N 6.1427306°E The Raschpëtzer Qanat is located NE of Helmsange in the commune of Walferdange, 10 km north of the City of Luxembourg. A qanat is an underground water management system consisting of vertical shafts connecting to a sloping tunnel designed to provide a supply of fresh water.
The Raschpëtzer is a particularly well preserved example of a qanat and is probably the most extensive system of its kind north of the Alps. It has been under systematic excavation for the past 40 years. To date some 330 m of the total tunnel length of 600 m have been explored. Thirteen of the 20 to 25 shafts have been discovered.
The qanat appears to have provided water for a large Roman villa on the slopes of the Alzette valley. It was built during the Gallo-Roman period, probably around the year 150 and functioned for about 120 years thereafter.