National Arboretum
I visited Alrewas last year while in the UK.
For those that haven't been, it is a stunning concept, and in twenty years or so when the 12,000 trees that have been planted grow a bit, it will be even more of a haven.
I found it a very moving experience just to walk around all those memorials, and especially the short stretch of the railway recovered from that infamous crime scene. Some people, relatives perhaps, had left little mementoes, and you'd be a hard man indeed to not feel the urge to shed a tear.
The food in the cafe isn't too bad either!