Travel to Shaded Woods' Ruined Fork Road and follow the path in the middle. Once you've reached the gate, wait for it to open as long as you have the King's Ring equipped. There are toxic critters in the area; before exploring, head straight to find the area's bonfire inside a broken house. Be careful when attacking these; they're fast and will gang up on you. Keep your distance or use powerful AoE attacks to take them out.
Find all the corpses in this immediate area to get the following items:
There's also a chest in the corner of the wall, far in the grassland. Don't open it since it's a Mimic. Kill it and loot the Sunset Staff and Dark Mask it drops. Now head to the stairs and find another corpse in the right side. Get a Fire Seed from it.
Continue upstairs and loot the body in the small pond to get a Radiant Lifegem. Check the left balcony to find another corpse containing Twilight Herb.
Continue inside and you'll be invaded by Aslatiel of Mirrah. Defeat him and open the next door. The corpse nearby only has a Fading Soul. As you get near the dragon skeleton, it will slowly come back to life. If you head straight at the ground floor, you can find a trapped man inside a magical barricade to the right. He will promptly tell you to leave him alone. The other corridor has several messages sprawled on the floor. At the end of a path is a lever. There's even a stern warning that says Don't You Dare!
Pulling the lever will free Navlaan. He will attack you if you're hollow so speak to him only when you're human. You'll be able to purchase the Astrologist or Black Witch Robe armor sets from him, elemental greatarrows to name a few. Take note that freeing Navlaan will also make him appear as an invader in different areas so weigh your decision before pulling that lever.
Now go upstairs and check out the corridor to the right. There's a chest at the end that contains a Great Magic Barrier. There are mirrors behind the stairs where an enemy may break free. Make sure to deal with them one by one. Loot the corpse to get a Northern Ritual Band +2 and Petrified Dragon Bone.
There's a petrified cyclops waiting on top of the main stairs; it's up to you if you want to use a Fragrant Branch of Yore or not to clear the path. Alternatively, there's a set of stairs to the left. Go upstairs to find a basilisk. You can attack it from a distance and kill it. Loot the Magic Stone it drops and the Crimson Water from the skeleton nearby. Head to the long corridor to the right to find a chest at the end. Loot the Bonfire Ascetic x2 from it.
Backtrack and head to the next room. Pull the string dangling from the dragon statue's mouth to open the path ahead. The path behind will close. Go to the next corridor where you'll find a Pharros Contraption to your immediate right. If you use a Lockstone on it, the whole corridor will be lit up.
Take out the Cyclops ahead and loot the corpse under the table to get a Radiant Lifegem. Continue a bit and you'll find a door to the left. Open it to find some sort of laboratory inside. Destroy shelves near the stairs to get a Radiant Lifegem from a corpse.
If you go downstairs, you'll find two beasts lurking in a corrosive pool. Remove your equipment before going to the pool to loot the items. Get the Large Soul of a Nameless Soldier and Corrosive Urn x4, Aldia Key, and Soul Geyser and Petrified Dragon Bone from the skeletons inside. Go back upstairs and leave the room.
Back in the corridor, continue forth a bit and you'll find yet another door beside a wiggling carriage. With the Aldia Key, you should be able to open it. Kill the enemy standing in front of the table then loot the corpse to get a Soul of a Proud Knight.
Up ahead is another enclosed enemy. Kill it if you want then find a corpse in the corner of the room. Loot it to get a Large Soul of a Brave Warrior. If you open the door nearby, you'll find a cyclops waiting behind the closed door. He's supposed to ambush you if you took the main corridor without taking the sidetrips so far. Kill it and take out the enclosed abomination along the main corridor if you want. The door nearby doesn't have any loot so you can just ignore it.
Continue forth and open the large door. Loot the nearby corpse to get a Simpleton's Spice and Twilight Herb. The door will burst open shortly, revealing yet another cyclops ready to take you down. If you freed Navlaan, he'll also invade you as a dark spirit in this area. After defeating the last cyclops and Navlaan, you'll find the misty door leading to the boss area.
Boss: Guardian Dragon
The Guardian Dragon's main attack is its fire breath, which will leave it vulnerable for several seconds. It will also occassionally fly away and attack with a fireball, capable of dealing splash damage so make suire to time your evasion. The best way to exploit it is to keep the right distance to make it use its fire breath attack then close in and attack. Getting too close will prompt it to swing its head twice, dealing heavy melee damage. Ranged characters will have an easier time dealing with this boss as well.
Leave the boss area and head towards the elevator. You'll find a corpse to your immediate right that has a Dragon Scale. Ride the elevator up and continue forth to reach a new area.
As you are facing down the stairs to the corrosive acid pool, its half way down the stairs on the left, press X for playstation or A for xbox... And it will open an illusion wall with the bonfire behind :-)
Where is the access to the #2 bonfire at 'Aldia's Keep' ???