Post Box and what?

A friend and I were on our way home along a road we have often travelled and I spotted these two; I didn't have a camera on me except my new trusty mobile which I can now receive my emails on!!

I wondered what the second box was as I could only see the back of it from the car; I still don't know what exactly it is..any ideas? I've never seen one before.

As you can see the weather is glorious today and warm enough to go without a coat.

Hope your having the same wherever you are cheers penny.