I've been to the Lake District a couple of times now. The first time was in 2006 with a big group and we all stayed in caravans near Keswick and went on lots of beautiful walks. More recently we stopped for a couple of nights on our way back from our Scotland trip and camped with our friends. We stayed at a National Trust campsite in Langdale. It was a really good campsite with a couple of pubs 10 mins walk down the road... one of them also owned by National Trust. I didn't realise National Trust did campsites or pubs, but both were brilliant and had really good facilities! The pub was super cosy with fireplaces, blankets, boardgames and all sorts of cute things... they also showed movies upstairs and the food was really good!
The only minor issue with this campsite was it was in a valley in England... where it rains! Our first night was good. The next day we explored the area, went for a walk and checked out the shops and had tea and cake in Ambleside. In the evening after dinner the heavens opened and it poured with rain all night. Chris and I had a particularly bad night as in the very early morning while the rain was hammering our tent we suddenly woke up to the hiss of our blow-up mattress slowly going down. It was a long, cold night. It is not fun packing up when everything is wet but being a National Trust Campsite they had this amazing drying room where we hung everything up to dry while we packed. At least it was the end of the holiday and we could go home for a hot shower... :-)