Now that you have put Knight Artorias out of his misery, you will have found a doorway to the left, this is locked for now, and to the right is the Battle of Stoicism, Dark Souls' PvP Arena. Level up and head, and prepare to fight some deadly new enemies ahead.
Head down the stairs and immediately to your left on the first platform will be an Oolacile Resident. Then jump onto the roof you see ahead to get a Large Soul of Proud Knight. You will also aggro 2 more Oolacile Residents. Kite these towards you and onto the platform above to deal with them.
Then, on the bigger platform you will face two more Oolacile Residents, kill these, and ignore the lift ahead and go towards and kill the next two Oolacile Residents. Then head down and on the platform to the right will be another Oolacile Resident in addition to an Oolacile Witch, then proceed towards the item to the far right, but beware the Oolacile Resident lying in ambush to the left.
Proceed down the stairs. At the next platform, hang a right and proceed down this path down, killing the Oolacile Resident along the way.
Drop down the the platform below and head into the building you see ahead. Watch out for the Oolacile Witch here and proceed down the stairs. Go all the way down for now and kill the other two Oolacile Witches, then loot the chest for a Dark Orb Sorcery, then head left up the stairs and follow the path. Kill this Witch to get the 'I'm Sorry' engraving.
Then, proceed inside the building and all the way to the top level where you entered, and take the exit to the left.
If you're looking for more help, our Dark Souls walkthrough and guide can help with all other areas of the game, including the dreaded Taurus Demon, Capra Demon, Ornstein and Smough bosses. Meanwhile, we have explainers on how to access DLC Artorias of the Abyss, the best gift and best class in Dark Souls, Dark Souls' best weapons, Dark Souls Covenants, Dark Souls Estus Flasks locations, Dark Souls Titanite Slab locations and NPC quests including Lautrec of Carim.
Head along the wooden ramparts, on the left you'll find a Soul on a corpse. Then and hang right and drop down to where we were before. Jump on this rooftop ahead and then again to the stairs ahead. Here, you will encounter two Oolacile Residents, be careful not to fall off and proceed along the narrow walkway towards the Witch, which you can kill with ranged attacks here.
Kill the Witch and proceed down the stairs. You will be jumped by another Resident to your left. Then, enter the archway and to the right will be another resident. As you approach the loot, another Resident will drop down and the loot is rubbish. Great.
Head down the stairs. Turn around to aggro a Witch and Resident. Kill both, and to the left exit will be a Soul of a Hero. Then, deal with the 3 Residents ahead and kill the Witch that is on the platform above. Exit this room
Follow the path and head right to unlock a shortcut to the bonfire. Proceed forwards to the left path that we ignored earlier. Aggro the three Residents, retreat out of the range of the two Witches, then head back in to take them down.
Proceed forwards to an enemy which you will be able to stunlock very easily. The Chained Prisoner has a limited moveset, and will be able to rush you down, so be sure to use a heavy weapon to stunlock and then enter the passage behind it. Kill the Resident that comes up the lift and proceed forwards to a bonfire.
Here, you will reach the Chasm of the Abyss.