Rift Quest:The Greatest Hunt  

To get to this Wardstone head northeast from Camp Cestus, a.k.a. the Portage Camp, and up into the mountains. When you reach the ridgeline head towards the peak, watching the downslopes for the Ancient Wardstone.

You can go through the cave-tunnel at Shatterstone Hold or go north then west to cross over the mountain.

The Altar is behind and on the west side of the landing across the bridge in Shatterbone canyon, and the spear is with Nomis' remains underwater amid the roots of the giant stump in the middle. Nothing attacks you, Calydon has died long ago.

Note: If you wait until you also have the quest At Any Price you can easily complete it from the Wardstone before you descend the mountain to find the Altar, or when you return to the Wardstone to complete this quest.