knacker's yard

noun2

1. •
   The area of a slaughterhouse where carcasses unfit for human consumption or other purposes are rendered down to produce useful materials such as glue.

   • [T]he market [Smithfield Market] is surrounded by slaughter-houses and knackers' yards, tallow-melting, bone-boiling, tripe-washing, and other offensive trades; [...] — 1855
2. •
   (informal, figurative) A (notional) place to send a person or object that is spent beyond all reasonable use.

   • I’ve never met someone so incompetent. He’s only fit for the knacker’s yard.