The group, from Aberdeen University, want the 38-bedroomed Dall Estate in Perthshire to become the new home of refugees wanting to live in Scotland.
The castle also boasts tennis courts, a golf course and an army assault course, all set in 265 acres - which dates back to the 1300s.
Darroch Bratt, who studies anthropology and archaeology, told the Press and Journal: "Basically, this came about by a total accident. I was looking through some property websites and this one caught my eye. So, I started talking about it with a few of my friends and we all agreed that it would be such a horrible waste to see it become another playground for the mega-rich. And we just felt that there had to be a better way to use all that land – we thought that housing conditions are generally not the best for refugees wanting to live in Scotland."
The group, who runs the Shared Planet Cafe in Aberdeen, is seeking donations from crowd-funding site Indiegogo and has a 28 December deadline.
