Some Neolithic cultures listed above are known for constructing megaliths. The Medway megaliths were built during the Neolithic era. These sites are home to prehistoric graveyards which contain hundreds of different megaliths. He mistakenly interpreted megaliths as Gallic tombs. The most widely known megaliths are not tombs. The most well-known rock art assemblage of Rapa Nui, however, are the "moai" megaliths. It is composed of a circle of megaliths surrounding a tumulus. The capstones of many southern megaliths have 'cup-marks' carvings. These standing stones are seen by many as genuine ancient megaliths. Archaeologists estimate that there are 15,000 to 100,000 southern megaliths in the Korean Peninsula. Some mainstream archeologists have participated in experiments to move large megaliths. On the younger level (II) rectangular structures with smaller megaliths have been excavated. Bena is also noted for its Stone Age megaliths. This unproven connection between druids and megaliths has haunted the public imagination ever since. As with northern megaliths, southern examples contain few, if any, artifacts.