Hamster loves to climb?

I recently made a bin cage out of a 110q Sterilite bin, and though my hamster seems to have stopped his cage biting, he keeps climbing the bars over and over again. He'll keep this up for hours and I'm really worried. As his cage lid is secure, I was considering getting some of the climbing decor you often see in snake/reptile habitats for him to climb on, as he really does love to get up high. Besides that I'm lost, he doesn't like his ball and my apartment has too many nooks for me to hamster-proof. Any suggestions?