Blink and you would miss it – but beneath an ivy-covered patch of grass between two gravestones in Highgate Cemetery lies a dark and troubled history.

The spot is the final resting place of 10 prostitutes, including a 12-year-old girl, who have been identified for the first time.

The Victorian women, seven of whom were aged 20 or under, were all residents at a correctional facility for prostitutes known as the Highgate Penitentiary, in North Hill, Highgate.

They had lain forgotten in Highgate West Cemetery for more than a century, but two of the graveyard’s volunteer tour guides, Rowan Lesson and Sam Perrin, made the discovery public for the first time this week.

“The age of some of these girls was a shock,” said Mrs Lennon, of Southwood Lane, Highgate. “Their grave is about a foot wide and there’s nothing there to recognise them.”

On why she chose to look into the penitentiary’s shadowy past, Mrs Lennon added: “Local history has always been one of my passions.

“I had never heard of the Highgate Penitentiary and thought it was a shame that these women were given no account.

“And of course, underage prostitution is still so relevant today.”

Emma Jones was only 10-years-old when she was first listed as living at the Highgate Penitentiary in 1861 and she died just two years later aged 12.

The last woman to be buried in the unmarked grave was Agnes Ellis in 1909, the second eldest of the unfortunate group at the age of 29.

It is not yet known what caused the women’s deaths.

Prostitutes who were sent to the penitentiary, which stood on the site of the current Hillcrest housing estate, were taught religion and domestic skills such as cooking and sewing in an attempt by clergymen to save the women’s souls.

The Romantic poet Christina Rossetti, who is also buried in Highgate Cemetery, often worked at the penitentiary to help the women secure employment before they left.

It is thought her relationships with the facility’s residents deeply influenced her poetry.

Ms Perrin, 38, of Palmerston Road, Bounds Green, said: “It’s a very important slice into Victorian social history. As a woman, I don’t think I realised how different it was to live as a woman 100 years ago.”