I suspect that many people will not think of Transylvania as an outpost.
It was, and in many ways still is, one of the last outposts to get to the East or to the West.
There were not enough people and to help a king of Hungary always was asking groups of people to come and protect the area. It was a large area and if it was a part of Hungary today would probably take up a third of new territory.
Still if it was an outpost what made it special?
The people. The mountains. The land.
The access to Rome.Vienna, Budapest, and other areas in Western Europe.
It still has many ancient cities and a long history. I am fascinated by it.