This riddle sounds like it is asking about some futuristic invention that can somehow see through solid walls.
But the answer is much simpler.
The clue asks:
“What invention lets you look right through a wall?”
Think about something that is built directly into a wall and allows you to see what is on the other side.
You use one in homes, offices, schools, and almost every other building.
It lets light come in and gives you a clear view outside without removing the wall itself.
Answer: A window.


