Heaven is where God awaits for people who already left the world. Heaven is where good people goes when they die. And as far as I know, Heaven is not located to somewhere. I don't believe that Heaven is actually up above in the sky because when you look up and fly, all we can see is clouds and birds. And beyond that is the outer space. And to the answer to your question is, Heaven is a spiritual dimension built for pure spirits and it can never be located.