It is usually one of the busiest days on the tourist calendar for Down County Museum, but yesterday public access to the historic building was prohibited.
The 18th century County Gaol in Downpatrick was securely sealed off from prying eyes as it was transformed into a production set for the filming of The Frankenstein Chronicles, starring Sean Bean.
Built in 1796, the former gaol provided the perfect location to shoot scenes for the highly anticipated six-part drama to be shown on ITV.
As news of the shoot filtered out, fans of the English actor, whose credits include Game of Thrones, The Lord of the Rings and Jupiter Ascending, turned up in the hope of catching a glimpse of the star.
But the building was securely cordoned off, much to their disappointment.
Downpatrick councillor Colin McGrath said it was "great news for the area" that the district has again been chosen to provide the setting for another major drama.
"Game of Thrones has been filmed in the area and now we have The Frankenstein Chronicles.
"There is a natural history around Downpatrick which is great for these type of films," the SDLP man said.
Mr McGrath added: "Down County Museum is a fantastic building and it is wonderful that it has been chosen by the production team. These TV programmes are helping to put us on the map."
Bean (55) has also been spotted shooting scenes for the programme across Belfast.
He is playing the role of Inspector John Marlott, working for Thames River Police.
The Rainmark Films production is a reworking of Mary Shelley's novel Frankenstein - which is about a scientist who creates a monster - and combines a detective drama plot with the original horror thriller story line.
Filming began for the period drama, which is set in London, in January this year.