Was this building an old castle?

Opened in 1858, just six years after the incorporation of the City of Joliet, the Illinois State Penitentiary, Joliet, now known simply as the “Old Joliet Prison,” has – for better or worse been – synonymous with the City of Joliet for nearly its entire history. The Joliet Prison, with its iconic castellated gothic architecture was designed by Chicago earliest architect W.W. Boyington, who also designed the Chicago Water Tower. Clipped from the history section of the prison web page.

Kudos to R Sims with the post. Yes it was a prison that operated in Joliet for many many years. They do give tours. Is not a castle was not a castle it is just the architectural style

Shot the blues Brothers movie there

They give tours.

No actually it's an old prison that shut down