There’s no romance in the red light district anymore, laments Louise Fokkens, as we walk through Amsterdam’s most notorious neighbourhood. “The brothels look like the inside of a hospital,” she gripes, with her thick Dutch accent. “When we were in windows we wore sexy clothes, but now they sit with plastic – plastic clothes, plastic tits, maybe even plastic…” I’ll leave it there.

Louise and her twin sister, Martine, who also accompanies us, have the dubious distinction of being the oldest sex workers in Amsterdam. The 74-years-olds have racked up more than a century in the trade between them and are estimated to have pleasured some 355,000 men, which is greater than the population of Iceland.

The sex workers in Amsterdam today have no class, claim the Fokkens Credit: GETTY

Despite their advanced years, it seems Martine and Louise Fokkens are still capable of turning heads. As we amble along Oudezijds Achterburgwal, one of the city’s oldest streets, eyes are drawn to their flamboyant apparel; the tight navy jeans, scarlet boots, red leather overcoats and blue berets, which sit atop wispy white hair. All matching, of course.

Though they have flirted with retirement, Martine and Louise are still active as prostitutes; the oldest girls in the oldest profession. They no longer sit behind the windows, but they keep a handful of regular clients. “They’re old clients,” says Louise, who speaks better English than her sister. “We’ve seen them for a lot of years. Some of them have become friends.” And some of them have wives. “If they can’t have it at home…” she adds.

Under a brooding Dutch sky, I hear how the key to being a successful sex worker is having good banter and creating a “fun and romantic” setting. “Don’t do it only for the money,” says Louise. And she seems to practice what she preaches, claiming, with an enthusiasm that seems entirely genuine, to enjoy her work. “It’s fun. Sometimes I think ‘ohhhh that’s nice’.” I proffer that it must get boring, at least occasionally. “No, nay, never," she says. "It’s a sport. You feel young.”

Martine in 2012, when she still worked behind the windows Credit: GETTY

Contrary to what people think, claims Louise, prostitution is not always about sex. “Sometimes we just have a drink – a cup of tea, coffee or a little gin,” she says. “Sometimes they also want a good time. SM maybe. Why not?”

The Fokkens know that retirement is just around the corner; the girls have to hang up their garters sooner or later. So in a bid to keep the money coming in, they’ve found new jobs as tour guides for a start-up called Red Light District Tours, which promises to peel back the curtain on the red light district and offer an insight into the lives of Amsterdam’s oldest sex workers.

“It’s very nice,” says Louise, when I ask about her new job. “We are also recording a CD.” They break into a song called When The Curtains Are Closed Again. Apparently, it comes out in July and will be the latest addition to the girls’ burgeoning collection of merchandise, which includes autobiographies and DVDs.

During our tour the girls, who starred in a documentary called Meet the Fokkens, are frequently interrupted by passers-by asking for photos. Ever the businesswomen, they use these interruptions as an opportunity to peddle their merchandise, which they haul around in a bag: those not willing to part with cash are denied a photograph and dismissed with a wave.

Martine and Louise tell me of the changes they have observed in the red light district. They claim Eastern European prostitutes, and the closure of many window brothels, has pushed Dutch prostitutes underground. “It’s terrible,” says Louise. “A lot of Dutch women are going on the streets and in bars and hotels.”

When we were in widows we wore sexy clothes Louise Fokkens

The girls are nostalgic for the “good old days” and linger wistfully outside a house on Koestraat, a quiet, bike-lined street on the edge of the red light district. “This was our first brothel,” says Martine, proudly. The Fokkens were among the first girls in Amsterdam to open their own bordello, where they made good money in what were challenging economic times. “It was a poor time for everybody,” says Louise. “[But] we had a nice car, nice holidays, good clothes, good eating – a good living.”

Opening their own brothel relieved the Fokkens of pimps, which the girls talk surprisingly highly of. “They were our managers,” says Louise. “Some were good; they drove you around, bought you dinner.” Most just wanted to save enough money to start legitimate businesses.

We stop for refreshments at an ice cream parlour, where the girls came as children. Those innocent days must seem a world away now; corrupted by a life working in the sex trade. Their account of Louise’s journey into prostitution is awful. Having mothered three children in her late teens with a man who, she claims, was prone to violence, Louise was taken to a brothel and told to work.

The girls are said to have pleasured some 355,000 men between them Credit: GETTY

“One Saturday evening I was going out with him,” she recalls. “I thought we were going for a nice evening and then he brings me there [to the brothel]. I started that night. I had to do it. I thought ‘okay it is a job, I’m making money’. And then at 10 o’clock he comes back to take my money.”

Louise escaped that dysfunctional relationship, but continued her career as a sex worker. Martine followed, having worked as a cleaner at her sister’s brothel where men would mistake her for Louise. When they realised there were two Fokkens, clients started requesting threesomes. “We did a lot of trios,” says Louise. Was that not weird, I ask. “No. It was fun.”

We did a lot of trios - it was fun Louise Fokkens

The girls have seven children between them, but neither of them are in relationships. “We have each other,” says Martine. They would be mortified if one of their daughters followed them into the trade (“we’d break her legs” says Louise), but both reflect fondly on their time in the red light district.

Meet the #Fokkens. The Dutch sex workers turned tour guides #Amsterdam A photo posted by Gavin Haines (@gavin_haines) on Sep 17, 2015 at 10:21am PDT

Over the years they claim to have pleasured priests, serviced the extramarital needs of couples and indulged in people’s penchants for a light beating. “Sometimes they like to get beaten,” shrugs Louise. “Why not?” Some have visited the girls to lose their virginity – often accompanied by their fathers. One of their clients got a kick out of pretending he was a donkey.

As the tour comes to an end the Fokkens leave me wanting more of their stories from the red light district. I ask a few final questions, but to no avail. “You’ll have to buy the book, sonny,” they remind me, before disappearing into the red light district; their red light district.

Amsterdam Red Light District Tour offer group tours with the Fokkens for €29.95, which can be booked via the website.