What better place to work out the tongue than a memorial to Friedrich Jahn, the German-born, Metro East-residing "father of systematic physical culture"? Jahn invented tumbling clubs, a.k.a. gymnastics societies, a.k.a. "turnvereins," back in Berlin in 1811. Exactly 102 years later, the St. Louis Chapter of the North American Turnverein donated an immense sculpture capped with Jahn's moppy head to the spot in Forest Park where the German pavilion had stood during the 1904 World's Fair. Northeast of the Saint Louis Art Museum, on a small slope overlooking a byway of the lagoon, the memorial is somewhat reminiscent of an amphitheater, with a bench and a mini-stage: a clean, placid place on which to wile away an afternoon cooing, "K¨ss mich! K¨ss mich!"