If i remember correctly you are still in act1 (which means there will be 3 of those entrances).

In act 1 in the main game, there are also 3 battlefield keys, like the one you found... each one will unlock ONE of those entrances.... i presume you will just have to run around a little more (since you dont want spoilers as to which entrance is where) in the battlefield to find the right one that is unlocked.

When you enter through the entrances, you will have 3 dungeon levels to clear of monsters.

NOTE: though its a common belief that you will find a boss-monster on the 3rd level, that is not guaranteed.... but then again in some dungeons you will find more than 1 boss on level 3, which makes up for it...



Your existence alone, is excuse enough for the creation of the entire universe… Il you my darling Jeanne-Dré 