Where is Injun Joe's hiding place when Tom Sawyer discovers him with his ill-gained gold?

In Mark Twain’s novel "The Adventures of Tom Sawyer", Injun Joe is a static character; he is the same at the end as he is in the beginning. He does not change through the course of any key events in his life. Finally, Injun Joe's hiding place when Tom Sawyer discovers him with his ill-gained gold is a small cave.

Injun Joe is a thieving, dishonest, wicked person who achieves most of his evil goals because he is also clever and resourceful. He kills young doctor Robinson without qualms for no discernible reason. He frames old Muff Potter and can get the people of the town to believe him. When proof of his part in the murder is about to be revealed, he reacts quickly and decisively at the trial. He jumps out a window and escapes. He cannot be found. His reputation is such that no one will confront him. People are too frightened to face him because they know that he will retaliate.

Injun Joe is central to the novel's primary adventure; he appears in some very important scenes in the novel. Again, he is seen murdering Dr. Robinson and framing the innocent Muff. He flees justice at Muff Potter's trial. He is the central figure in the search for buried treasure. He shows up, disguised as a deaf and mute Spaniard, in a haunted house where Tom and Huck are hiding. Later, his extreme cruelty is seen in his plans of revenge on the Widow Douglas. When Tom encounters Injun Joe in his cave, he is finally trapped with his ill-gained gold and dies a befitting but horrible death.