From Wikipedia:
Hogan's Heroes is an American television sitcom that ran for 168 episodes from September 17, 1965, to March 28, 1971, on the CBS network. The show was set in a German prisoner of war (POW) camp during the Second World War. Bob Crane had the starring role as Colonel Robert E. Hogan, who coordinated an international crew of Allied prisoners running a Special Operations group from the camp. The program also featured Werner Klemperer as Colonel Wilhelm Klink, the commandant of the camp, and John Banner as the inept sergeant-of-the-guard, Schultz.
The setting was a fictional version of Stalag 13, a POW camp for captured Allied airmen located north of the town of Hammelburg in the Bad Kissingen woods and run by the Luftwaffe. Its location was on the Hammelburg Road (now known as E45), on the way to HofburgStrasse and eventually Dusseldorf. One episode mentions they are 106 kilometers from Heidelberg, but that measurement is actually aviation miles; it would have taken 199 km (124 mi) by car.
Stalag 13 bore no resemblance to its real-life counterparts, Oflag XIII-B and Stalag XIII-C. The show's premise was that the POWs were actually active war participants, using the camp as a base of operations for Allied espionage and sabotage against the Germans or the German Armed Forces. The prisoners could leave and return almost at will via a secret network of tunnels and had radio contact with Allied command. They were aided by the incompetence of the camp commandant, Colonel Klink, and the Sergeant Of The Guard, Sergeant Schultz. Hogan would routinely manipulate the incompetent Klink and get Schultz to look the other way while his men conducted secret operations. Klink and Schultz were in constant terror of being transferred to the Russian Front, and Hogan took pains to keep the hapless German duo firmly in place. Klink had a perfect record of no escapes while he commanded the POW camp. Hogan actually assisted in maintaining this record, and made sure any prisoners who needed to be spirited away had been transferred to someone else's authority before their escape was enacted. The program for a sitcom was unique as it combined elements of surrealism and dynamic action/adventure storytelling.