A pillbox is a type of blockhouse, or concrete dug-in guard-post, often camouflaged, normally equipped with loopholes through which defenders can fire weapons. It is in effect a trench firing step, hardened to protect against small-arms fire and grenades, and raised to improve the field of fire.
A World War II hexagonal pillbox on the bank of the Mells River at Lullington, Somerset, England
A British mini-pillbox in Jerusalem, Israel
A British World War II type 22 hexagonal pillbox in Kelling on the North Norfolk coast, England. The pillbox broke up during winter storms in February 2021.
A British World War II type 25 circular pillbox on Sheephatch Lane near Tilford in Surrey, England
A blockhouse is a small fortification, usually consisting of one or more rooms with loopholes, allowing its defenders to fire in various directions. It is usually an isolated fort in the form of a single building, serving as a defensive strong point against any enemy that does not possess siege equipment or, in modern times, artillery, air force or cruise missiles. A fortification intended to resist these weapons is more likely to qualify as a fortress or a redoubt, or in modern times, be an underground bunker. However, a blockhouse may also refer to a room within a larger fortification, usually a battery or redoubt.
Completed in 1750, Fort Edward in Nova Scotia, Canada is the oldest remaining military blockhouse in North America.
Reconstructed European wooden keep at Saint-Sylvain-d'Anjou, France, has a strong resemblance to a North American western frontier log blockhouse
The Henrican blockhouse at Mount Edgcumbe near Plymouth, Devon, which is believed to date from circa 1545
Blockhouse of Westreme Battery, built in 1715–16 in Mellieħa, Malta