German K5 Railway Gun...
...an example at the Batterie Todt in France
The German K5 railway gun was a 280mm gun used in WW2 and 25 were built. Two survive. One is at the Aberdeen Proving Ground in Maryland, USA, and is named Leopold. It was found in Italy shortly after the fall of Rome in 1944. A second one is in Europe, and can be found on display at the Batterie Todt museum on Cap Gris Nez in Northern France. I took these pictures of the example in France back in 2009, while the gun was undergoing some restoration and repainting. There are models of the K5 available in a/144 (Dragon) 1/72 (Hasegawa and Hobby Boss) and 1/35 (Dragon and Trumpeter). While the models are impressive, seeing the real thing is something you will remember, it is huge. At the Batterie Todt Museum it is kept alongside the museum bunker, which is one of four that housed huge 380mm guns in equally impressive concrete emplacements.