Four thousand homeless people sleep rough every night in Berlin, with more arriving every week. But for many of the city's residents, these people barely register their existence.
Yet the city can look very different when seen through the eyes of those weighing up a safe place to sleep, looking for food, or in need of medical help. Querstadtein is a new project that wants to show people what Berlin looks like to the homeless - and is offering tours of the capital by guides who themselves used to live rough.
"We hope that the participants get a different view of Berlin," said 30-year-old project co-founder Sally Ollech. "I want to open my eyes," said tour participant Jutta Blümel, who booked herself on the tour after reading about it in the paper.
Poverty and homelessness are some of the city's biggest problems, she said, adding that she wishes more people would help out - by working in the soup kitchens for example. "There are so many opportunities," she said.
For €9.40 ($12.05), curious visitors get taken on a 90-minute tour of the city's main landmarks for the homeless - including the Zoologischer Garten station, where the Bahnhofsmission charity doles out meals to around 700 people every day.
The area around Zoo station is first port of call for Berlin's homeless, explained tour guide Carsten Voss, 54, who himself used to sleep rough in Berlin until a few months ago. As part of the tour, the former manager tells his groups how he came to lose the roof over his own head.
"Then came the burn-out," he said. Voss stopped going to work and withdrew from society, losing all contact with his friends and family. Eventually, he got chucked out of his flat for not paying his rent and stayed for a short time in a friend's summer house before finally landing on the street in the winter.
He gravitated back to the street in Berlin's Schöneberg district where he used to live - only this time he was sleeping on a park bench.
"Lots of people who become homeless stay in their neighbourhood," said Ollech, and added that stories like Voss's helped the project challenge some commonly held assumptions about homeless people.
Many often believe those sleeping rough are drug addicts or alcoholics and physically in a bad state, but often they are not easy to recognize straight away said Voss, who now has a flat and lives on benefits.