The NWA United National Championship (often abbreviated to UN Championship) was a professional wrestling championship sanctioned by the National Wrestling Alliance, and best known for being defended in All Japan Pro Wrestling. It was unified into the Triple Crown Heavyweight Championship, along with the PWF World Heavyweight Championship and the NWA International Heavyweight Championship, in 1989. The original belt remained in use for the Triple Crown until 2013.
References
NWA United National Championship Wikipedia(Text) CC BY-SA