There is a bus from Braga to Montalegre stopping in Venda Novas, 4 kms away from Salto and 8 kms away from the gathering. You can check timetables in http://www.transdev.pt/bdtweb/line.php?operator=3&line=4.
Road to parking is good enough to arrive by autovan.
From the parking to the gathering there are 2 kms of light steep.
We'll publish the easiest way to arrive with public transport from Barcelona and Madrid when we have the information.
Peace & Light.