A megalith is a large stone that has been used to construct a prehistoric structure or monument, either alone or together with other stones. There are over 35,000 in Europe alone, located widely from Sweden to the Mediterranean sea. The word was first used in 1849 by the British antiquarian Algernon Herbert in reference to Stonehenge and derives from the Ancient Greek words "mega" for great and "lithos" for stone. Most extant megaliths were erected between the Neolithic period (although earlier Mesolithic examples are known) through the Chalcolithic period and into the Bronze Age. Types and definitions While "megalith" is often used to describe a single piece of stone, it also can be used to denote one or more rocks hewn in definite shapes for special purposes. It has been used to describe structures built by people from many parts of the world living in many different periods. The most widely known megaliths are not tombs. Single stones Menhir Menhir is the name used in Western Europe for a single upright stone erected in prehistoric times; sometimes called a "standing stone". Monolith Any single standing stone erected in prehistoric times. Capstone style Single megaliths placed horizontally, often over burial chambers, without the use of support stones. Multiple stones Alignments Multiple megaliths placed in relation to each other with intention. Often placed in rows or spirals. Some alignments, such as the Carnac Stones in Brittany, France consist of thousands of stones. Megalithic walls Also called Cyclopean walls Stone circles In most languages stone circles are called "cromlechs" (a word in the Welsh language); the word "cromlech" is sometimes used with that meaning in English. Dolmen A Dolmen is a stone table, consisting of a wide stone supported by several other stones Cist A Cist is a small stone-built coffin-like box or ossuary used to hold the bodies of the dead. Burials are megalithic forms very similar to dolmens in structure. These type of burials were completely underground. Timeline Mesolithic 7400 BC: A 12 m long monolith probably weighing around 15,000 kg found submerged 40 m under water in the Strait of Sicily south-west of Sicily. Its origin and purpose are unknown. Neolithic 9000 BC: Constructions in Asia Minor (Göbekli Tepe, Nevalı Çori and other sites); perhaps proto-Hattian, a yet to be named culture (the oldest discovered ceremonial structures in the world). 7000 BC: Construction in proto-Canaanite Israel (Atlit Yam). 6000 BC: