Four days to hold 116 events - and boundless goodwill. This is what is asked of the organisers and volunteers who run Sheffield's Heritage Open Days, which return next week from Thursday to Sunday.
The goal is the same as ever - helping people to discover something new, unusual or surprising about the city, while helping to foster a sense of pride in Sheffield.
But the history festival's popularity has grown rapidly, with the number of individual happenings more than doubling since 2015 as new groups, societies and enthusiasts have become involved.
"It proves there's an appetite and an audience for more heritage events," says Louise Watt, from the Sheffield Civic Trust, who co-ordinates the open days with fellow trust member Liz Godfrey.
The recent expansion means the festival's annual booklet, detailing all 116 listings, is an even richer treasure trove. There are many churches to see, and sites that played a role in Sheffield's history of steel manufacturing, as well as offbeat events with a novel take on where heritage lies.
Important places in the city are opening their doors once again, too. There is a full day of family activities planned in the Botanical Gardens on the Sunday, free guided tours of the Cutlers' Hall are happening on the Saturday and there will also be walks around the Assay Office, the Catholic and Anglican Cathedrals, the Central Library and Town Hall.
Shake-ups in Sheffield are set to be reflected as well. John Lewis is making its festival debut, offering a tour of the Barker's Pool department store built in the early 1960s for Cole Brothers which could soon be demolished to make way for a 'new generation' shop in the city's retail quarter.
And The Star's editor Nancy Fielder is hosting talks at its offices next Thursday and Friday as the newspaper prepares to move up the road from York Street, where the publication has been based for the entirety of its 130-year history.
Louise thinks the open days are a 'force for good'.
"Some people say it makes them proud to be from Sheffield. That's such a good thing."
With limited funding, the events run largely on a spirit of benevolence and charity - which money can't buy.
"I think one of the reasons so many of the smaller organisations have got involved is that it's not daunting," Louise says. The festival is spread around the city, she adds, rather than focusing solely on affluent areas.
"It's not just the well-heeled of S10 and 11 in sensible shoes going to see a house where steel magnates once lived."
There is a feeling among the Civic Trust that the events could be of much greater value to Sheffield. Louise says there is an economic boost in terms of visitors' spending, as well as less tangible benefits.
"There's a monetary advantage to this but there are other things like social cohesion."
Louise cites the Madina Mosque on Wolseley Road's involvement, for the first time since 2015, as an worthy example.
"There were an awful lot of people who went to their open day. People found a welcoming atmosphere there, and I really think that's great."
Libraries in Broomhill, Ecclesfield, Stannington, Walkley and Upperthorpe are running events next week, spreading the word about their past and future at a time when many such facilities are being handed over to the community.
"They're going to be what we have now, we're not going to have many libraries that are municipally funded," says Louise. "We thought this was a good kicking-off point for them to bring more people in. They need a constant supply of volunteers if they are to keep going, I would imagine."
Open days taking an unconventional look at Sheffield life include the chance to explore a prototype eco-home made from shipping containers at Heeley City Farm and 'drainspotting' walks around Heeley, which comprise a journey around the suburb piecing together a story from lampposts, pillar boxes and manhole covers.
Examples of lesser-known architecture from 1900 to 1999 will be the points of interest on a guided stroll with Andrew Jackson, of the Yorkshire 20th Century Society, on the Sunday.
"I suppose we're very glad that so many people want to take part," says Louise.
The challenge, she concludes, is to build on the open days' success by seeking more resources to realise the festival's full potential.
"Once it's all over we are aiming at a big Heritage Lottery Fund application, which needs time taken over it, and the right focus. It can't be taken on by the local authority, it's got to be done in a different way."
Visit www.heritageopendays.org.uk for details. Booklets are available from the Sheffield Tourist Information Centre, next to the Winter Garden.
Don't miss The Star's series of five special features, each previewing a different Heritage Open Day, from tomorrow until Saturday.