July 17-19, 2015 – Breathe – A Slackline & Discovery Festival – Chicago, Illinois
“Breathe gives participants a safe and supportive slacklining, yoga and musical experience while also offering a space to nurture self-reflection. This is not just a festival, but also an opportunity to help transform from within, by engaging in physical activities both meditative and challenging.” – from http://www.discoverbreathe.com
For international events, check out Slackline Festivals. They do a great job of organizing and posting relevant event information.