ok lets see, it doesnt seem to be on earth.
now, outside the earth, in the universe, its not habitable, its either too cold or too hot in space, depending where you are.
another thing is, it requires physical death to get there afaik, so how the ones of muslim faith think they will benefit from the virgins promised to them?

I assume for the sake of this thread that "religious nutcases" refers to theists in general or anyone with religious beliefs? Although, this thread also appeared to call out Muslims specifically, but from an evangelical, born again Christian, bible beating, uneducated, moronic, religious nutcase perspective I assume you're referring to the "third heaven"? Not necessarily the heavens in which we can see the birds flying through or the heavens in which the stars and planets are seen, but that heaven or "paradise" that is beyond our ability to see where God the Father resides? If that's the question then Christian scripture indicates it being located in the northern heavens beyond the stars. Where is it located exactly? I don't know.
Again, this is just a Christian, religious nutcase perspective....thanks!!