Dennis the Cat has the only marked grave inside the walls of the Old Idaho Penitentiary.( Idaho State Historical Society)

In the past, we’ve told you about some of the fascinating history of the Old Idaho Penitentiary in Boise, from haunted cells to rose gardens to notable prisoners who lived behind the stone walls.

But we haven’t talked about one of the best-liked and most respected residents of the Old Pen, Dennis.

Dennis lived at the prison between 1952 and 1968 and when he died, the prison population buried him in the only marked grave inside the prison walls. And oh yeah, it might be worth mentioning that Dennis was a cat.

This Sunday marks the third annual Dennis the Cat Day at the Old Idaho Penitentiary and we wanted to find out what all the fuss over this feline was about. So we asked Alexandra Polidori, the event coordinator at the Old Idaho Pen, to join Idaho Matters.