Useful tip: When camping out in the wild always boil any water you get from a mountain stream. When camping in the Brecons There was a stream that ran down from the mountains at the bottom of the field where we pitches our tent. But we always went into Brecon to get our water from a standpipe. Always be careful with the water you drink as it invariably has parasites in it if it comes from a stream and probably animal poo as well.