On September 28, 2006, in the Vlinderbuurt, on the corner of Eikenpage and Vredenoordlaan, The sunken fountain by visual artist Hans van Lunteren unveiled. A metal grid is set into the floor, incorporating the leaves of the ash, birch, maple and poplar: trees that grow in the immediate vicinity. The composition of the leaves is built up from a slight rotation, as if the wind has created a small vortex with a still interior. Under the grid is an armature of three consecutively stacked bowls, into which pumped-up water fell until 2023. The inspiration for this work of art was the impressive soil remediation that took place in Kralingen between 1994 and 2000 on the site of the former gas factory. The underground fountain was designed as a visible and audible image of the purified groundwater. Until 2023, the groundwater was pumped up and purified, but the contamination of the soil has now been resolved and no more water flows to the work of art. In order to preserve the drastic soil remediation in the collective memory of the district, Van Lunteren will allow the work of art to enter a new phase in 2024: from now on as The sunken fountain at restThe fountain is returned to nature and becomes a source for mosses, ferns and other plants. Nature is given free rein and the well can softly green.