BS The Legend of Zelda/Map 1/Dungeon 1
Head west. Kill the enemies and grab the Compass. Go through the door and kill the Stalfos (one carries a Key). Now head back to the entrance. This time go north. Kill the snakes to get another Key, then unlock the door and head north. Kill the Stalfos and unlock the door with the key you got earlier. In here grab the Map and kill the enemies to open the door. Head west.
Kill the enemies and head west. This room has some spike traps. Walk forwards and then backtrack to make the spikes hit, then dash across while they are reversing. Push the western corner of the diamond aside and go down the stairs. Grab the Bow and head back upstairs. Now go east one room, then north. Kill the enemies and grab the Key, then head west. Kill the enemies in order to make the lone block pushable; use it to open the door. In the next room kill the enemies and use a key on the door. In the next room are some Stalfos (one carries a Key). Use this key on the door to the north, then head north again.
In this area kill the enemies to get some Bombs. Head east. This room contains a door and a Key, but also some Wall Masters (if they catch you they will hurt you and drag you back to the entrance of the dungeon). Kill them if you wish, and then use the key on the locked door.
You'll now fight your first boss, Aquamentus. Aquamentus spits three fireballs at a time that arc outwards. You can use either your bombs or your sword beams (if you still have full health), or else time your movements in-between the fireball blasts. Once Aquamentus is defeated collect the Heart Container, go into the next room for your first Triforce piece, and this dungeon is done.