In this no-post version of an early airmail stamp, a small prop plane flies over Oslo's Akershus Fortress. Akershus was started in the 1290s to defend Oslo, and has survived all sieges. It surrendered without combat to Nazi Germany in 1940 when the Norwegian government evacuated the capital. After World War II, eight Norwegian traitors, including Vidkun Quisling, were executed there. Through its history it has been used as a prison and a burial place for Norwegian royalty. Today it is open to the public daily. Come visit and watch the skies for classic airplanes. And be sure to wear your new airplane t-shirt!