'Waassertuerm' is Luxembourgish for water tower: Limpertsberg's, on Avenue du Bois.
The tower was built in 1902 to plans by city architect Antoine Luja, beside an 1886 reservoir on the highest point of Limpertsberg. According to the city, it served as a balancing reservoir, keeping water pressure steady for the quarter. Now out of service, it has been on the national monuments inventory since 9 November 2017.