A slaughterhouse or abattoir i/ˈæbətwɑːr/ is a facility where animals are slaughtered for consumption as food for humans. Slaughterhouses that process meat not intended for human consumption are sometimes referred to as knacker's yards or knackeries, used for animals that are not fit for consumption or can no longer work on a farm such as horses that can no longer work.
Slaughtering animals on a large scale poses significant logistical problems, animal welfare problems, public health requirements, and environmental problems. Due to public aversion in many cultures, determining where to build slaughterhouses is also troubling.
Animal welfare and animal rights groups frequently raise concerns about the methods of transport, preparation, herding, and killing within some slaughterhouses under the example of animal rights activists such as Howard Lyman and Ric O'Barry.
Until modern times, the slaughter of animals generally took place in a haphazard and unregulated manner in diverse places. Early maps of London show numerous stockyards in the periphery of the city, where slaughter occurred in the open air. A term for such open-air slaughterhouses was shambles, and there are streets named "The Shambles" in some English towns (e.g. Worcester, York) which got their name from having been the site on which butchers killed and prepared animals for consumption.