Memory of Orro:

First things first, head straight up the stairs and clear out those pesky bandits. You'll spot a contraption that needs a Pharros Lockstone – go ahead and use one to open up another room.

Inside that room, you'll find a trap chest (watch out!) and another contraption. Don't mess with the second contraption, but look to its right. There's an illusion wall there. Bust through it to find a chest containing the Steel Armour set.

Now, backtrack a bit and take the lower path. This next big area is crawling with enemies. You'll see a regular Giant and a Warrior Giant. Be careful, the Warrior Giant's attacks can go right through your shield! Luckily, they're busy fighting some NPC soldiers, and they'll do most of the work for you. If you've got some Poison Arrows, they make this whole encounter a breeze. Keep an eye out above you as you enter; there are archers on scaffolding. Feel free to explore this area a bit, there are some minor treasures scattered around.

When you're ready, head to the far end of the area and go up the staircase. You'll find a fallen giant. Examine him to get the Soul of a Giant. You can examine him again to leave the area early.

If you're aiming for the Grand Lance, you'll need to head back inside and make your way all the way up to the roof.

Up on the roof, you'll find a Sorcerer Giant and another regular Giant duking it out. Just hang back and let your poison arrows do the work – they're pretty easy to take down from a distance.

At the far end of the roof, you'll see a few contraptions. Hit the one on the left. This will break something and cause a platform to lower.

Carefully drop down onto that platform. From there, you can jump into the building through the hole in the roof. Inside, there's one more giant to defeat, and then you can help yourself to two chests.