After having moved to Berlin and finally found an apartment which I share with four+ Germans, I went last weekend to the open air festival Nation Of Gondwana. This is a minimal techno festival which takes place just one hour outside of Berlin, surrounded by a beautiful forest and a small lake. The last 3 days before the festival had been cold and rainy, but just in time the weather cleared up and was perfect during the whole festival weekend.
To go to the Nation Of Gondwana, take the train (about 4 euro one way from Berlin) to Bahnhof Nauen and from there the free shuttle bus that goes about every 30 minutes to the festival area. If you are not travelling with a tent, Woolworth in Germany have a cheap 2-3 person tent for around 20 euro. Price for the two day festival is 30 euro, which includes a trash fee of 5 euro that you get back if you collect your trash and leave at the exit. If you like camping a good idea is to come one day before the festival to enjoy the beautiful area.