Frankburg is a city around the cities of Goodminton and Haffaton, referred to as 'outpost'.
It was captured by forces of Goodminton from Haffaton - together with another outpost, Hamfurter - with help from Wanda's uncroaked.IPTSF Text 7
It may have belonged to Haffaton originally.
Outpost probably refers to a Level 1 city.
Real World References
Names of Frankburg and Hamfurter recombine the names of cities in Germany - Frankfurt and Hamburg with a possible reference to hamburger and frankfurter.