PAULINE James, in hard hat, cap lamp and wellies, is standing up to her ankles in water in a tunnel in the dark, explaining how lead mines work. Outside in the sunshine, Ruth Lax has been feeding the hens and collecting eggs.

Later they might dig the garden, talk about insects with small children, proggy mats with pensioners, or production figures for lead in the 19th century with Germans.

If nothing else, Information Assistants at the North of England Lead Mining Museum at Killhope are an adaptable lot.

And, ironically considering that in its working heyday Killhope was such a man's world, many, most indeed, of them are women.

"Mainly because it's part-time, which is handy if you have a family," says Ruth, who's worked at Killhope for 11 years. "And if the worst comes to the worst, you can bring your children to work" - which has to be a bonus.

"We do all sorts of things here. We might start the day preparing the washing floor where the children can splash around separating the lead ore from the waste. We might have a school group in. They can range in age from five to 18 years old and we stay with them for the day. Exhausting, but usually very enjoyable.

"You have to be adaptable. They might be here for A-level work in geology, in which case they want to know facts and figures. Or it might be an end of term treat, in which case they just want to enjoy themselves."

Pauline, whose sons are long since grown up, used to work in marketing for Marks & Spencer and was a hairdresser but she and her husband moved up to Weardale "because we just love it up here". And now she's worked at Killhope for six years .

The assistants take it in turns to lead the groups into the old mine - a real mine, with a bit of reconstruction in the middle. In white wellies, with helmets and lamps, the tourists look a strange sort of working party.

We plodge in, water running out towards us out of the hillside. The tunnel is narrow. The entrance behind us gets smaller and more distant. The roof gets lower until we are all walking along bent double, watching our feet, banging our helmeted heads, and with our noses somewhere near the waistband of the person in front.

In our group are a couple of bright and interested children and their parents, a lady of 82 hanging on to her nephew, a man who thinks he already knows it all and a couple of people who suddenly decide that they can't after all face the dark, and go splashing at speed back to the sunlight.

Pauline keeps the group together, intrigues the children with talk of boys their age who were in an accident in the mine in 1864. Graham Peart was killed in a fall. His friend Thomas Rowell survived for three days in the total darkness by eating the tallow candles. As we take this in, their story, their memory hovers in the shadows of the lamps.

Pauline explains the workings of the underground water wheel, tells of another grisly death, agrees with the pensioner about the bad old days.

Then she makes everyone switch off their lamps and we stand in the dark, the noise broken only by the trickle of the water and the tap tap tap of a distant miner (thankfully a recording, not ghosts)... And it suddenly hits us, just what it must have been like to spend our working days in here, in the dark, in the wet, for precious little reward.

"Let's face it, you have to be a bit of a performer," says Pauline afterwards back in the sunshine, when she's made sure all her group are out and checked the lamps, helmets and wellies back in. "Every tour's different because you have to tailor your information to the people who are in it."

It's the sheer diversity of the visitors to Killhope which makes it unique and which makes the job so interesting - as well as challenging.

"There's everyone from families on holiday and just wanting to have a few hours fun to people who are fascinated by industrial archaeology. The Germans and Dutch always want to know masses of facts and figures about the mine and its history," says Pauline.

"Then there are families who are coming back. Maybe they or their parents moved away from the dale. Their grandparents might have worked in Killhope or one of the other lead mines and they want to find out about their own history."

Killhope is also surrounded by woodland and nature trials. New this year are brilliant little backpacks full of handy equipment for budding young naturalists. The backpacks - also sorted by the information assistants - can be borrowed free from the museum.

"We do all sorts of jobs about the place, but the most important one is talking to people, trying to explain what Killhope is about, getting visitors to understand how small the world was then for the miners and their children. Amazing now to have their descendants coming here from America," says Pauline.

Then there are those panicky people to deal with and the occasional badly behaved child. "It's still a real mine. You have to be very aware of safety," says Pauline.

Ruth used to work in Aycliffe Young People's Centre so her experience might just give her an edge. She's from Alston, worked in a number of places, lived in Yorkshire and loves being back in the high Pennines. "It's just such a wonderful part of the world that I love promoting it," she says.

Although they are part-time, Pauline and Ruth and the other core staff - unlike the casual and seasonal staff - work all year round.

"In the winter we come in to do maintenance work, lime washing the buildings, for instance - now that really is a horrendous job, but it has to be done. Lifting up the hotching tubs isn't fun either," says Pauline.

"Being in the shop - the reconstructed lodging house where the miners lived during the week - is very nice, you just sit and chat to people about the miners' lives. But it's not so pleasant when you're out on the washing floor in the driving rain or you're being bitten to death by midges.

"But I can't imagine doing anything else now. Killhope is a wonderful place to work - and a wonderful place to visit."

* The North of England Lead Mining Museum at Killhope is open from 10.30am-5pm (5.30pm Bank and school holidays) until October 31.

l There are special Santa weekends in December, and you can book now for these.

l A facsimile copy of the Lindisfarne Gospels is on show at Killhope until September 11.