About the forts

[Myxir]

Hey, i looked for the fort names in the internet, and this is what i got:
Aggersborg:

Aggersborg is the largest of Denmark's former Viking ring castles, and one of the largest archeological sites in Denmark.

Trelleborg:

Trelleborg is the southernmost city in Sweden and the seat of Trelleborg Municipality in Skåne County. It has a population of 25,643 (2005).

Samal:

Samal is a 4th class municipality in the province of Bataan, Philippines.

All quotes are taken from wikipedia. The others i didn't find. It would be intresting to know why NGD named the forts like they are named now