If you've read "The Cask of Amontillado"...?

Question

Where had the stone and morter, used by Montresor to wall up the entrance to the niche, been hidden?

Answer 1

at the far end of the crypt into which montrésor leads fortunato there is a pile of bones on one side of the room:

At the most remote end of the crypt there appeared another less spacious. Its walls had been lined with human remains, piled to the vault overhead, in the fashion of the great catacombs of Paris. Three sides of this interior crypt were still ornamented in this manner. From the fourth side the bones had been thrown down, and lay promiscuously upon the earth, forming at one point a mound of some size.



the tools, brick and mortar are hidden beneath this pile:



As I said these words I busied myself among the pile of bones of which I have before spoken. Throwing them aside, I soon uncovered a quantity of building stone and mortar.

Answer 2

Behind the wall. Who cares?