Using bottles and paper towel rolls I took out of our recycling trash, we were able to construct this makeshift marble run. (Ignore the ugliness that is my wall).
I cut the bottoms off of plastic bottles and cut paper towel rolls in half then taped them to the wall.
Lots of trial and error work needed before we got a successful marble run.
Kids did need to climb a chair to insert marbles.
For much older kids, you can use this activity to demonstrate a variety of concepts from physics including:
Here are some other fun ways to make your own marble run:
cut open a pool noodle from Family Fun
Use a cereal box and toilet paper rolls from This Momma Loves