A fireplace is an architectural structure designed to contain a fire. Fireplaces are used at the present time mostly for the relaxing ambiance they create. Historically they were used for the practical purposes of heating, cooking, and heating water for laundry and domestic uses. A fire is contained in a firebox or firepit; a chimney or other flue allows exhaust to escape. A fireplace may have: a foundation; a hearth; a firebox; a mantelpiece; a chimney crane, used in kitchen and laundry fireplaces; a grate; a lintel; a lintel bar; overmantel; a damper; a smoke chamber; a throat; a flue. On the exterior there is often a corbeled brick crown; the projecting courses of brick act as a drip course to keep rainwater from running down the exterior walls. A cap, hood, or shroud serves to keep rainwater out of the exterior of the chimney; rain in the chimney is a much greater problem in chimneys lined with impervious flue tiles or metal liners than with the traditional masonry chimney, which soaks up all but the most violent rain. Some chimneys have a spark arrestor incorporated into the crown or cap.
Fireplaces have variable heat efficiency. Organizations like the Environmental Protection Agency and the Washington Department of Ecology warn that, according to various studies, fireplaces can pose a significant health risk. The EPA writes "Smoke may smell good, but it's not good for you."