During an average summer, the trickle of visitors to Bankfield Museum, hidden away on a leafy road leading out of the town centre, is steady but unspectacular, averaging around 6,000 between July and September.
But this year, something remarkable happened in Halifax - over 16,000 people passed through the doors of the grand 19th-century building in just three months.
They were there to see a display of the costumes that appeared in the hugely popular BBC period drama Gentleman Jack, about the life of local heiress Anne Lister.
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Now, Calderdale Council have confirmed the exhibition will be extended for a further two months due to an unprecedented appetite for the recreated Georgian finery.
After opening in mid-July, this weekend (October 26) was meant to mark the end of the event, but it will now run until Monday December 23.
Between July and September, there were 16,500 visitors to the Bankfield, compared to 6,000 during the same period in 2018.
Staff have been astonished by demand to see the displays, which has exceeded all expectations.
'Gentleman Jack tourism' has seen thousands of fans from all over the world descend on the area to visit locations that appear in the series, including Shibden Hall, the Lister family's ancestral seat, which is owned by the council and open to the public, along with its parkland. Many buildings on the Shibden estate that date from Anne's time can also still be seen.
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Coun Susan Press from Calderdale Council said:-
“We’re thrilled to extend the Gentleman Jack costume exhibition, which can only be seen in Calderdale and is free to visit. We want to make sure as many people as possible have the chance to see it before it closes.
“We have been overwhelmed by the phenomenal response to not only the costumes at Bankfield Museum, but also Shibden Hall where Anne Lister lived, and to Calderdale as a destination. Visitors are travelling from across the globe to see items and places which help them to feel closer to Anne’s legacy.”
Items in the exhibition are on loan from Lookout Point, the production company that has also been contracted to shoot the second season, which is based on Anne's personal diaries.
They include the now-iconic top hat worn by Suranne Jones as Anne, which was considered unusually masculine for the period, and dresses seen on her same-sex partner Ann Walker, played by Sophie Rundle. Male characters' costumes are also on display.
Anne has been labelled 'the first modern lesbian' after entering into a marriage 'ceremony' with Walker, who was also from a Halifax mill-owning family, in York. She died at the age of 49 of a fever while the couple travelled through eastern Europe.
How Gentleman Jack sparked global interest in Shibden Hall
Meet the fans from all over the world who turned up on the opening day of the exhibition
The garments were in storage at the museum in Boothtown - itself an ornate mansion once owned by mill baron and MP Edward Akroyd - for several months, with strict instructions that they could not be unveiled until the end of the series.
Elinor Camille-Wood, head curator at both Bankfield and Shibden, predicted that the exhibition would be the most popular in the museum's 120-year history.
"We are so lucky to have got the costumes - we had them for weeks, but there was a final episode embargo.
There are 12 dressed mannequins plus cabinets displaying a range of accessories
"The reaction has been amazing. We've had so many messages of support from all over the world, and our social media accounts have gone mad. People are spending a whole day at Shibden and Bankfield and exploring the wider area too, which has so much to offer.
"We've had visitors from the US, Germany, France, Australia - a lady from the US rang us up and asked where the nearest airport was as soon as she heard about the exhibition! It shows the depth of passion there is for Anne Lister and Gentleman Jack.
"We knew it would be popular as it's such a powerful story and people are so inspired by it.
"We don't have Anne's long black coat, but we are planning another exhibition of outfits designed by another company, so we hope to have it then."
Elinor is revelling in Halifax's moment in the sun, signposting Gentleman Jack fans to locations scattered all over 'Callywood'.
"They are astounded that Shibden is still there and that it is cared for so well. They love the mix of country and town here. They say how lovely and welcoming the staff are and it's given us a real boost.
"We've also had a lot of local people come who said they hadn't visited since childhood."
Among the international contingent crowding into Bankfield for the launch of the exhibition were two fans from Belgium and America.
English teacher Janne Monballiu, from Antwerp, was already aware of Anne Lister but has enjoyed exploring Yorkshire and following in her footsteps.
"I'm a big fan of Sally Wainwright's work and it's culminated in such a brilliant series. I have a lot in common with Anne Lister and the show just clicked with me. It's the first time I've been to Yorkshire and I love the area - there is nothing to compare it to in Belgium.
"I've been up to Shibden every day since I got here to walk around, and I love the exhibition - the attention to detail is just amazing."
Shantel Smith, from North Carolina, is such huge Anne Lister fan that she has booked tickets for every talk and event she can find about Halifax's most famous daughter.
"I came to London in May and thought, since it's so close I might as well go up to Halifax. I love it here. I've been to all the events with authors and historians - anything that's on the calendar. I've driven all over Yorkshire looking at the locations from the series.
"Anne's diaries have really lasted the test of time - they are so detailed. She's really intelligent, although she has some quite conservative views so I'm not sure we'd be friends today! It's fascinating to be able to connect her writing to real history, it's not just fiction. The TV show has been amazing - before it was shown, I didn't know she existed."