"What's beyond the known limits? 
What's past the edge of our maps?
The
ultimate version of this question is, what lies outside the boundary of
the universe?
The answer is … well, it's complicated.
Even if the universe is a formless, shapeless, nameless void of
absolutely nothing, that's still a thing and is counted on the list of
"all the things" — and, hence, is, by definition, a part of the universe.
If
the universe is infinite in size, you don't really need to worry about
this conundrum.
The universe, being all there is, is infinitely big and
has no edge, so there's no outside to even talk about."
Space.com
But there is an "outside" to talk about---- I knew a man in Christ above fourteen years ago, ...such an one caught up to the third heaven. 2 Corinthians 12:2