In each city there is a Guild and you can accept Hunt Quests from them.
After accepting a Hunt Quest, the target monster will appear within a dungeon.
Depending on the monster, there are times when they are hiding in an area not displayed on the dungeon map.

Hunt Quests have recommended levels from Lv 5~100, but if you have confidence, you can challenge them without regard for the levels.
You can also receive experience points and drops for defeating the enemy.