Ok OrangeRakoon said I could make the first proper dungeon in 'Tales of Illusia'. As it is in a mountain side, it has a cave like theme and feel.
The main item is the boomerang, and is (as you can see) obtained from one of the villagers cells. The sub-boss is the Octo-shield, and the main boss is The Arrghus style boss that Marshmellow made. (See below for strategy).

Ok, strategy time.
Dungeon 1 (Supeskia): Mountain Labrynth1). As you enter, go down the stairs into the room with the four zols (green slime ball things) and the two keese.
2). Head left, and avoiding the spiky guy, left again into the room with the traps.
3). Head down, kill all the keese and a key drops from the ceiling.
4). return to the previous room, but this time head left. In here, knock the four... things into the holes and a chest containing the compass will appear.
5). Return again, but this time head up, avoiding the laser. knock the other... thing into the hole and another key will drop.
6). Now head ALL the way back to the room with the four zol and the two keese, and open the door above.
7).
SUB-BOSS: Octoshield. Ok, i believe to kill him, you avoid his lasers, and when he charges up the next one you run behind him and attack with the sword. Repeat until dead. A staircase will appear, leading down. Enter them.
8). In this side scrolling section, pick up the dungeon map from beneath the structure thing, before heading out.
9). In here kill the two armos guys and use a key on the left cell's door. Talk to the woman and she will run out. Open the chest to get thr boomerang.
10). Hit the switch across the holes with the boomerang, which opens the right cell. Enter and talk to the other woman who also flees. Open the chest for 20 rupees.
11). head back into the Octoshield room, and back down. Go left into the room with the spiky guy, and get the key from across the blocks with the boomerang.
12). Head back to the room with the rotating laser where you get the second key: now head up.
13). In here, kill the 5 zols and 2 keese. (Remember, the other 3 keese are in a different room). Once dead, a key will fall into the hole. Take the stairs down. Use your boomerang to obtain the key.
14). back to the Octoshield room again, but now hit the switch to your left with the boomerang. head up.
15). Push the block forwards, and head left. Walk down the corridor with the three keese into the room you were in a moment ago, (Except you'll obviously be on the other side). Open the chest for the boss key.
16). Head back into the block pushing room, and enable it so you can head right. In here kill the Like-likes, Stalfos' and various other stocking fillers for a piece of heart.
17). Now, in the previous room head up into the boss room.
18).
BOSS: Arrghus guyTo kill this guy I think you should pull off the mini eyes with the bommerang and kill them individually. This causes him to open his eye. Hack and slash, and repeat until dead.
19). Collect the heart container and head up into a big important looking room. Because I don't exactly know what the dungeon reward is, I left it empty for OR or u-f-o to decide whats in there.
Wow, i didn't realise it was so long!!!