Where is Heaven, and What do we do When we get There?

About a week after our neighbor's dog died, Godzilla and I were sitting on the front porch taking a break from our street-ball game when he asked me "Where is Heaven? I don't think its underground." That's his little mind still working through this new concept of death. We had driven past several graveyards in the preceding week and talked about how people are buried there so their families have a place to go and remember them.

He knew though that those graves just couldn't be where Heaven was. So, we talked about it. Threw some ideas out there. Had a laugh and pondered God and Great Grandpa chillin' up in the clouds. I had to ask him what he would do if he could just be floating around up in Heaven with anyone he liked. Perhaps sharing a smoothie with Superman? Baseball with the angels? Nope, he wants to go mountain climbing with me.

So, now the question is do they sell "Mountain Climbing for Dummies" in Heaven, or should I start reading up on it now?