How do you complete Castle Sol in Elden Ring? As part of our ongoing Elden Ring walkthrough, we're going to guide you through another optional location worth exploring: Castle Sol. Fully exploring the area will eventually pair you up with the Commander Niall boss fight.
As part of our Elden Ring guide, we're going to reveal how to complete Castle Sol. This page is broken down into specific objectives to help you through the castle and eventually find the Commander Niall boss encounter.
Elden Ring: How to Complete Castle Sol
On this page, we're going to explain how to complete Castle Sol and then find the Commander Niall boss.
Castle Sol Walkthrough: How to Find It
Castle Sol is located in the north of the Mountaintops of the Giants. From the Freezing Lake Site of Grace, follow the path northeast until you're able to get up into the area above with multiple enemies roaming. Follow this path all the way west. You'll know you're heading in the right direction if you encounter huge skeletons appearing out of the ground and then encounter the Death Rite Bird.
You can choose not to fight the boss and push on down the path to the east that'll take you to Castle Sol. Continue riding Torrent in this direction and the location will come into view, with the Castle Sol Main Gate Site of Grace sitting by its entrance.
Castle Sol Walkthrough: Find the Church of the Eclipse Site of Grace
As soon as you walk through the Castle Sol entrance, you'll be greeted by two Lion Guardians. These are tough opponents you shouldn't be fighting both at the same time, so if you want to challenge them, focus on the one roaming the main area and then go for the one on the right. If you manage to kill them, each one drops a Somber Smithing Stone , Beast Blood, and an Old Fang. There's also a Golden Rune  on a corpse to the right of where the first Lion Guardian came from.
Once they're dead, head forward and up the wooden staircase leading left. You can also grab a Smithing Stone  off another corpse underneath the wooden platform. At the top and to the left at the end of the path will be some Freezing Grease, but otherwise, press forward.
Up ahead will be one of those incredibly annoying birds as well as two wolves to take down. On the corpse to your right is some Thawfrost Boluses. Go indoors through the passage ahead, take the wooden stairs up to your right, and take on the soldiers outside. Just beware of the powerful knight that spawns on the stone steps as you approach. Exploring this area yields more Thawfrost Boluses and a Golden Rune . Inside the upcoming building will be the Church of the Eclipse Site of Grace. Rest up and approach the altar in the church to speak with a Ghost and pick up the Eclipse Shotel.
Castle Sol Walkthrough: Find the Commander Niall Fog Door
Take a left out of the church and through the doorway ahead to get back indoors. On the first floor inside will be a Smithing Stone  hanging off a corpse, but beware of the enemies that spawn around you once you pick it up. Once they're dead, push on through the building. Two more ghostly knights will spawn at the exit. On the other side of them will be the Fog Door leading to Commander Niall, but be sure to operate the level to your left before heading inside.
This activates a lift that creates a shortcut back to the Castle Sol Main Gate Site of Grace and opens up more of the castle for you to explore. Once you're rested up and ready, head through the Fog Door to challenge Commander Niall.
Castle Sol Walkthrough: Kill Commander Niall
In order to complete Castle Sol, you must overcome Commander Niall. For an overview of the boss fight and strategies for beating him, click the following link: Elden Ring: How to Beat Commander Niall.
Do you have any other helpful tips and tricks for how to complete Castle Sol in Elden Ring? As always, check out our Elden Ring guide, and let us know in the comments section below.