Hoghton Tower kicked off the third episode of season five of award-winning British crime drama when it aired at 9pm on Sunday (September 1).
The iconic fortified manor house in rural Chorley doubled up for St Hilda's Orphanage in Birmingham, a beneficiary bankrolled by the Shelby Family's Grace Shelby Foundation.
The tense scene put the shows leading characters Tommy Shelby (Cillian Murphy) and Polly Grey (Helen McCrory) against the orphanage's Mother Superior (Kate Dickie), where the powerful duo questioned her over reports of nuns beating children with bricks and hoses.
Tommy and Polly withdrew funding from the orphanage with the orphans re-homed in the Shelbys' own institutions.
Hoghton Tower took to Facebook hours before the airing of the show to let its thousands of followers know about the appearance.
The post attracted more than 300 comments and 200 shares from fans of the show celebrating the local shout out - as well as saying how gutted they were at missing the likes of Murphy visting the area.
Sue Percival commented: "I knew they filmed there, my friends works there and told me but I couldn't say a word till now, can't wait to see it on Peakys."
Gemma Fisk added: "If only I'd know they was so close to were I live!"
Jasmine Turner said: "This is the hall where we had our wedding ceremony and wedding breakfast."
Keelie Bentley said: "As if Cillian Murphy was this close to me and I had no idea."