Everything that isn’t tech is a very, very large set. What I assume the OP is really saying here is a “screen fast”. Reading is nearly the same activity for our text-scrolling-addicted brains. I recommend _anything_ outside even if it’s just sitting and staring. Eventually you’ll fill that time as long as you have discipline for no-tech.
Not OP but theres tons of stuff. Go to the gym, fish, go to the shooting range, visit a museum, find a super long nature trail and go as far as you can, etc. Even in small nowhere-towns there are tons of things to do when you let your imagination run wild. Finding stuff to do without computers is a skill we have as kids, but lose once we gain our careers.