- "The final resting place for all contraband within Hill Valley, the decycling bin ensures that socially toxic items will never find their way back into the hands of the general public in any way, shape or form."
- —Danny Parker Jr.
The decycling bin was a type of disposal system invented by Citizen Brown in an alternate timeline. It was located in the Hill Valley Courthouse Square near the base of the clock tower. Marty assumed it was simply a concrete garbage can container, but later learns it's actually the mouth of a tunnel. Very few people knew where the decycling bin led to, as the large tube traveled underground, crossing underneath the town square, and into the former El Kid speakeasy beneath SoupMo. It was assumed that things thrown inside were incinerated, but in fact they were sorted and stored in the speakeasy. The reason for this is unknown.
In 1986 of this timeline, Biff Tannen, under the influence of his Citizen Plus wristwatch and the control of Marty McFly, heaved himself headfirst into the decycling bin in order to retrieve certain tapes with evidence that citizens of Hill Valley were miserable under the rule of First Citizen Brown and his wife. Marty had assumed that Biff would be able to easily reach inside and grab the tapes from the bottom of the 'can'. Shortly after, Marty discovered its true nature as a tunnel on close examination and followed Biff. Inside El Kid, Marty discovered everything that had been confiscated from the citizens of Hill Valley that had not been destroyed.