Everything he said.
It's a fantastic place. I've been going for the last 15 years, generally camping
here and I never get bored of it. You always seem to be within an hour of something to do, which is great.
For walking, try
here Quite descriptive with a few photos to tempt you.
My wife loves it in Keswick. It's a 2 mile walk from where we camp, and we tend to walk halfway round Derwent water, then drink a bottle of champers next to the lake and watch the sun go down.

You just can't get bored of that.