Slate

are recurring NaN Items and NaN Objects in.

The four NaN Slates are found in the OoA:. Within the OoA:, the OoA: contains a giant stone tablet sitting on a pedestal, with receptacles for the slates surrounding it. When all four are placed into their receptacles, the larger stone tablet will part, exposing the staircase that leads to the OoA:'s OoA:, OoA:.