You won't get to Spiral Chamber until it is your time grasshopper. You will need to complete certain quests to get there. I will tell you that you have to fight a ghoul to get the key for it and the door is in Ravenwood. As for Collossus Blvd., It is not required to complete it to get to the Spiral but it is fun to complete.
you get a spiral key when you deafeat nightshade and then you get the key to krok land thats your first land so then you get to go in but you talk to bartlby first
