Ashlar masonry is a type of building construction that uses primarily rectangular blocks of stone. Using techniques dating back thousands of years, ashlar masons can create walls, arches, and buildings through correct placement and varied sizes of rectangular blocks. Ashlar masonry is seen in many ancient buildings, and still plays a major part in construction in some parts of the world.
The blocks used in ashlar masonry may vary in size; some modern experts refer to any ashlar block with a height less than 11 inches (27.9 cm) as small or little ashlar. Most ashlar blocks are ground especially smooth with parallel faces, so that they can be tightly fitted together without mortar. This type of masonry is often referred to as dressed stone, because the faces are sometimes embellished or decorated with carvings.
The origin of ashlar masonry is not entirely clear; many ancient cultures include early examples of the building technique. The Knossos palace in Crete, the step pyramid of Djosar in Egypt, and Macchu Picchu in Peru all show signs of ashlar construction. The building style was prized for its stability; the sturdiness of the tightly fit stones provided a strong and formidable structure that, in some cases, has lasted nearly 5000 years.
Although some of the more famous examples of ashlar masonry are simple, straight walls, the technique can also be used to create domed or arched structures. By using progressively smaller blocks, curved structures can be created. Beehive-shaped tombs called tholoi are commonly found structures throughout ruins of ancient civilizations in the Mediterranean, and many were constructed of ashlar blocks topped with a domed cap stone.
The mysterious order of Freemasons revere ashlar blocks as symbols, using them metaphorically to describe the process of enlightenment. According to Freemason beliefs, a person who has not yet gained enlightenment is similar to a rough-faced ashlar block, while those who have been enlightened have been ground and carved to a perfect, useful, smooth ashlar block.
Ashlar masonry is still used in modern times, though the exceptionally long construction process may put some people off. To achieve an ashlar look without the lengthy and difficult process, some builders place a stonework veneer over an already constructed structure. Yet for large buildings and edifices, this type of masonry remains an impressive an historic choice, uniting modern building skills with a masonry tradition known since the earliest days of human civilization.