Just because we're not ready to take on the DragonLord doesn't mean we're not ready to explore Charlock a little... only a little, though. An NPC in one of the towns made a passing mention about there being a hidden passage behind the DragonLord's throne, so that's how you're supposed to know to check here.

Hidden in Charlock Castle is one of the most powerful weapons in the game, a sword said to be able to cleave through steel... and we're gonna be REALLY happy to have that (assuming we can even live long enough to find it).