Kreacher's den

""So, this is Kreacher's bedroom?" said Ron, strolling over to a dingy door in the corner opposite the pantry. Harry had never seen ity open."

—Ron Weasley, Harry Potter and the Order of the Phoenix.

We first see the little compartment when Harry, Ron and Hermione go down to the kitchen to give Kreacher his Christmas present (a ptachwork quilt to "brighten up" his bedroom).

Inside the Den
The den is wear Kreacher sleeps, eats and hides all sorts of things. It is located in the kitchen at Number Twelve, Grimmauld Place, under the pipes. In it, you will find:


 * A very large old-fashioned boiler (which took up most of the space)
 * A nest-like jumbled pile of assorted rags and smelly old blankets (with a small dent to show were Kreacher curled up to sleep every night.
 * Stale bread crusts and mouldy bits of cheese
 * Small glinting objects and coins
 * Shattered, silver-framed, black-and-white photos of the Black family (his favourite one being Bellatrix Lestrange, as it is the only one with it's glass clumsily mended with Spellotape
 * Nature's Nobility: A Wizarding Genealogy 
 * A hiddem dead mouse

Appearances

 * Harry Potter and the Order of the Phoenix (Frist appearance)
 * Harry Potter and the Deathly Hallows