The distance from the Darknar Castle to Paragon city was roughly around 10-15 minutes on a carriage, or riding on horseback and depending on the speed of the mount one used.
Normally, the castle of the Lord would be built in the center of said Lord's capital city, or in this case where the castle was built first, the city would be built around the castle.
However, the demon king's castle was a different story.
Even in the past, the castle had existed outside the fallen Darknar city. This was because the castle was the demon king's residence as well as a treasure trove of insanely valuable wealth and Magic knowledge and resources.
Thus, not only was the castle a prime target for his enemies, but it was also the one place where he would be the most vulnerable. As the demob king was someone that could use all manner of magic, it was reasonable to assume that the castle would contain the most comprehensive collection of Magic knowledge known to man.
