Building on IvanaK's idea:
A young child walks to a big wall. It's tall, but not too tall it couldn't be climbed. He has a backpack and climbing gear so he looks like a real explorer. With confidence, the kid begins to climb the wall, curious to see what is on the other side. As he climbs, the wall appears neverending. But he doesn't give up and keeps climbing. As he climbs, he grows older and older until, finally, he gets all the way to the top and he is an old man. The wall is now much much taller and bigger than it was when he started climbing, but he is now up in the sky. From the perspective of the other side of the wall, we see his head appear over the top. We're looking directly at his face but we can't see what he is seeing. He looks amazed and dumbfounded by what he finds there. "The Other Side" is written on the wall below his head.