The Old Idaho Penitentiary hosts its fourth annual Dennis the Cat Day, celebrating the beloved feline mascot who lived at the prison from 1952 to 1968. On this special DAY, visitors can learn about Dennis' unique story and his lasting impact on the site. Buried within the main yard with a dedicated headstone, Dennis remains the only marked grave within the prison walls.

Learn more here: instagram.com/oldidahopenitentiary