an Entity references as follows:
The Neptune Grotto (German: Neptungrotte) close to the Obelisk entrance in Sanssouci Park, Potsdam, was created by Frederick the Great between 1751 and 1757 to beautify the park. Built following plans by Georg Wenzeslaus von Knobelsdorff it arose as a representation of the revived interest in garden architecture. The grotto ought to have been a component of the numerous fountains of the park, which did not function at that time, owing to a lack of technical knowledge.