A drug house or crack house is a building where drug dealers and drug users buy, sell, produce, and use illegal drugs, including crack cocaine. In this way, crack houses are not unlike the earlier opium dens of the late 19th and early 20th centuries. Often they are old, abandoned or burnt-out buildings, oftentimes in an inner city neighborhood. However, in response to increased community scrutiny and law enforcement activity, drug operations are moving from the inner cities to the suburbs, in an effort to blend in.