Those who have been playing Final Fantasy XV for quite a while will have noticed that there is a door in every dungeon that will not open. That's because the only thing that could open them is the Sealbreaker's Key. Here's how you can do it.

When you think you've finished Final Fantasy XV, there are more adventures to discover postgame since there are still a lot in the dungeon extensions. In order to open the dungeon extensions, you need to acquire the Sealbreaker's key.

Provided you finished all the dungeons and defeated the final boss, you can then go straight towards the Meldacio Hunter headquarters which you can find on the northwest part of the world map. The outpost is located at the northernmost part of the road that leads to Vesperpool.

Then, find Ezma at the Risorath Basin and speak to her. She will give you a quest called Menace Beneath Lucis. You can never miss her - just look for an old woman wearing eyeglasses. After completing the quest, go back to Ezma again and she will hand you the Sealbreaker's key that will allow you to open all eight dungeons.

Be careful because behind these eight dungeons lie a powerful monster that is more powerful than the last one. If you want to successfully finish each dungeon, make sure that you have the recommended level to do so.

The first one, Balouve Mines requires you to have 75 level while Costlemark Tower needs 95 and Crestholm Channels should have 99. Others include Daurell Caverns -70, Fociaugh Hollow - 60, Greyshire Glacial Grotto - 65, Keycatrich Trench - 50, and Steyliff Grove- 85.

These are not just the postgame goodies you can find in Final Fantasy XV. The game also reveals some important stories that gives the Final Fantasy storyline a conclusion.