In Assassin's Creed Valhalla, you can find Offering Altars. On this page of the guide, you will learn where to find the altars. This will make it easier for you to max out the Snotinghamscire region.
You will find this offering altar in the northern part of the region, right next to the synchronization point.
You need 3 pieces of titanium to complete this side activity. You will get them by exploring the game world.