Some time ago a correspondent sent BWTAS a postcard of a water tower they had picked up on their holidays. They hadn't seen the tower but thought it was nearby. The card didn't name the tower and no one here had any idea where it was but now it turns out to be in Langeoog, (its name means 'Long Island') one of the inhabited Frisian islands in the southern North Sea belonging to Germany. Maybe this is a case of mystery marketing; "this is wonderful, don't tell anyone" is an effective tourism pitch.
Its clean air, low in pollen and particulates, made Langeoog very popular in the 19th Century as a health resort. The 1908 tower is the island's symbol and a tourist attraction. Living on what is not much more than a big sand dune in the ocean, fresh water is evidently precious to the residents. This tower is a European example of what is common in the USA of a water tower becoming the town's symbol and appearing on all its marketing materials and civic insignia.
Cars are not allowed onto the island and with its miles of deserted beaches, open skies and water sports, Langeoog is still a popular holiday destination which is why many photos of the tower appear on sites like Flickr. The rapidly changing light and weather reward the patient photographer. If you want to see what it's like now, there's a webcam pointed at it here.