The Crestfallen's Retreat
Be careful of the undead enemies here. They're fast and they unleash a series of quick slashes so make sure to take them out one by one and avoid getting surrounded. There's a corpse across the stream where you can get a Lifegem. Just as the stream turns, you'll find a bonfire up the small alcove to the right. Light the bonfire and continue forth.
Carefully cross the stream as there are two enemies here and an archer. Lure the enemies behind the rocks to prevent the arrows from reaching you. There's a lurking undead swordsman near the archer that you need to lure as well so be ready not to get flanked. At the end of the stream is a corpse that can be looted. However, be careful of the undead axeman that will stand up and ambush you. Loot it to get a Soul of a Lost Undead.
Continue uphill through the giant tree roots and climb the ladder. There are three enemies lurking around above so prepare for battle. You can lure them towards the other ladder leading to a tower ruins and dispatch them one by one. Loot the corpses here for a Lifegem and Human Effigy. There's an archer in the ledge above so be careful not to get sniped. The white knight sitting on the tree can be fought and defeated. Just make sure you dispatch the archer on the ledge above. We'll get to that so just ignore him for the meantime. Loot a Broken Straight Sword from the corpse beside him.
Leave the area for now and head to the other exit where you'll find a ladder attached to a ruined tower. Climb it and take out the two undead soldiers along the stairs. Follow the path and carefully go through a narrow pathway near the edge. This will take you to a corpse containing a Soul of a Nameless Soldier.
Follow the path and you'll reach the ledge where the undead archer is. Take him out and do a sprint-jump across the gap to loot the corpse in the end of the ledge. Obtain a Shortsword and Soul of a Lost Undead. Backtrack to the where the White Knight is sitting and fight him if you want.
His attacks are slow but has a broad range so make sure you have enough stamina to evade. You can always fall back to the ladder to reset his position and do some annoying hit-and-run on him. Be wary of his charge attack though as it can take you by surprise. Upon defeat, you'll get a huge amount of souls and a Heide Knight Sword.
Once he is defeated, head to the misty entrance. Be careful of the corpse near it since it will be reanimated and attack you. Go through the tunnel DO NOT enter through the crack on the wall. Carefully turn to the left. There's an undead axeman who will ambush you here so prepare to dodge away. There are two undead in the room to the right so get their attention and lure them. Enter the room they're in and destroy the bookcase to find a corpse behind it. Loot it to get x20 Wood Bolt.
At the end of the corridor is an undead knight wielding a two-handed sword. Defeat it and continue upstairs. There's an archer at the end of the path so unless you're using a ranged weapon, you don't have any choice but to rush to it. Be careful though since there are enemies waiting outside, including an undead that lobs fire bombs. Don't hesitate to fall back to the hallway as necessary. Once the archer is down, go up and get near the undead swordsman. If you're at a distance, he'll throw fire bombs at you so get near him so you can easily evade his melee attacks instead. Take out the undead axeman and loot a Buckler from the corpse nearby.
Climb up the ladder near the stairs and head towards the corpse at the end of the balcony. Be careful since there's an undead pikeman that will spring back to life as soon as you get near. Pick up x5 Witching Urn from the corpse and then open the door in the building to find a bonfire inside.