One year ago, a young woman was repeatedly gang-raped on a moving bus in Delhi, India. The student, who had hopes of becoming a doctor, died two weeks later.
The attack, so brutal in its nature, was met with outrage across the world. Tough new laws were introduced in March 2013 which allowed the death penalty - carried out very rarely in India - to be handed down in the most serious cases of rape and, in September, four men were sentenced to death.
The case sparked a national debate about the treatment of women in India. Young, female students protested in droves, stating, "This victim could have been me." It gave them a voice and a platform in which they were able to speak openly about the harrowing realities of city life for many girls and women.
As part of the Because I am a Girl Urban Programme, a collaboration between Plan International, Women in Cities International (WICI) and UN-HABITAT, a study was conducted to understand how safe and inclusive cities really are for adolescent girls and it was published earlier this year.
Of course, the mistreatment of women is not confined to India - it's a global issue - so girls from across the world, including Cairo, Hanoi, Kampala, Lima and Delhi, were asked to share their views about the city in which they live.
Insecurity, sexual harassment and exclusion, were issues that cropped up numerous times, and it's essential these issues are noted and taken seriously.
Why? Well, not only is it a basic human right to feel safe in the place in which you live, but for the first time in history, there are more people living in cities than in rural areas.
Each month, five million people are added to the cities of the developing world, and it is estimated that by 2030, approximately 1.5 billion girls will live in urban areas.
The girls interviewed by Plan in Delhi shared stories about how suffocating, not to mention dangerous, it could be to live in a city that felt unsafe.
"Girls venture out of their homes only when they feel safe," revealed Rehana, 15, from Delhi. "We've had many unfortunate incidents here, so there are times girls don't go out of their houses in fear. How long can we continue with this fear?"
The fear of going outside, making that simple journey to go to school, is so engrained in society, that Rehana's father will watch her from a distance to make sure she reaches school safely. He has even adjusted his working hours so he can escort her home.
Public transport also remains a constant source of danger, especially in Delhi, where the attack took place. Buses are often rowdy, overcrowded and unsafe, which can lead to sexual harassment, says Rehana.
"There was an elderly man who was standing behind me on a very overcrowded bus and after a while he started to touch me inappropriately. I felt very uncomfortable and told him to go away," recalls Rehana. "He started doing it again. I had a safety pin on my necklace. I took it out and I pricked him with it really badly. Only then he moved back."
Many girls in Delhi also revealed how darkness leaves them feeling vulnerable and open to violence. Kiran, 16, who took part in a safety walk in Delhi (an exercise where girls mapped the risks of their city), recalled how girls said it was difficult for them to go out after dark as they were harassed, ogled and laughed at by groups of men and boys.
Public toilets were another issue, says Khushbu, 16.
"I met a girl who recalled an incident where she and her grandmother needed to use a local community toilet. Her grandmother stood outside while she went in. Once she was inside, a man grabbed her from behind. She scratched him with her nails and managed to escape. The girl and her grandmother started screaming and called the police who arrived and arrested the man."
One year on, 'justice' might have been served, however it is clear much still needs to be done to improve the safety of cities for girls and women, not just in India, but across the world.
This study provided an opportunity for girls and women to speak about the issues they face and that need to be tackled, while the horrific attack on 16 December 2012 provided the fuel behind the fire, giving females the determination to make a stand.
Safe, reliable public transport is needed. Clean, free, safe accessible public toilets are essential. Parks and public spaces need to be well-lit and an increase in policing and security needs to be put in place.
But most of all, girls need to be given the opportunity to speak out about their experiences and voice their concerns. And, if the influx of girls into major cities continues, it's essential the authorities sit up and listen to them.
To find out more about Plan International's Because I am a Girl campaign, visit plan-international.org/girls/