The Aqua Publica Gate leads to the valve chamber of Arlon’s first water tower, built on the forecourt of Saint Donatus’ Church in 1893, no longer in use. Water was brought here from the Grübermühlen springs near Oberpallen, 6 kilometres from Arlon, using pumping machines and a carefully designed supply network. This mechanism shows how early infrastructures managed to supply the upper town with water.