The biggest and most successful homeless charity is the Arrels Foundation, which is located on Carrer de la Riereta, in the Raval neighborhood. It has been running since 1997, and it works directly with homeless people, providing housing, meals, attention and healthcare. It also works with the public trying to raise awareness for the issue. Since it started, nearly 20 years ago, they have been able to successfully re-home over 9000 people. They accept donations via their website, and are always looking for more volunteers.
Photo by Nicolas R