OSLO, NORWAY—The Associated Press reports that an exploration of the 100-acre area surrounding the site of southeastern Norway’s Gjellestad ship with ground-penetrating radar has detected a cluster of Iron Age longhouses and several burial mounds damaged by plowing. Lars Gustavsen of the Norwegian Institute for Cultural Heritage Research (NIKU) said the largest of the structures measures about 197 feet long and 49 feet wide, making it one of the largest known in Scandinavia. The poorly preserved Gjellestad ship, which has been dated to between the late eighth and early tenth centuries, measures more than 60 feet long. Further research will help Gustavsen and his colleagues determine how old the houses are and how they were used. To read about a Viking sword unearthed in southern Norway, go to "Artifact."