Portal tomb is an ancient structure that consists of large stones that support a capstone, designed to create a burial chamber. It is also known as a dolmen or cromlech. These synonyms are derived from the French "dolmen," which refers to the two long stones that form an entrance to the tomb. "Cromlech" is a Welsh word, which means "bent stones." This describes the structure's shape, with the capstone leaning against the supporting stones. Other synonyms for portal tomb include megalithic tomb, chambered tomb, and burial chamber. These are structures built during the Neolithic period and are found in various parts of the world, typified by their large size and unique architectural designs.