Scandinavia") published in 1885, which is still in wide use. His relative chronology has held up well against radiocarbon dating, with the exception that the period's start is closer to 1700 BC than 1800 BC, as Montelius suggested. For Central Europe a different system developed by Paul Reinecke is commonly used, as each area has its own artifact types and archaeological periods. A broader subdivision is the Early Bronze Age, between 1700 BC and 1100 BC, and the Late Bronze Age, 1100 BC to 550 BC. These divisions and periods are followed by the Pre-Roman Iron Age. Culture Settlements Settlement in the Nordic Bronze Age period consisted mainly of single farmsteads, which usually consisted of a longhouse plus additional four-post built structures (helms). Longhouses were initially two aisled, and after c. 1300 BC three aisled structure became normal. Some longhouses were exceptionally large (up to about 500 m2 in area), and have been described as "chiefly halls", "the sitting area of which is the size of a megaron in contemporary Mycenean palaces". Larger settlements are also known (such as Hallunda and Apalle in Sweden and Voldtofte in Denmark), as well as fortified sites, specialist workshops for metalwork and ceramic production, and dedicated cult houses. Settlements were geographically located on higher ground, and tended to be concentrated near the sea. Certain settlements functioned as regional centres of power, trade, craft production, and ritual activity. The Bronze Age fortified town of Hünenburg bei Watenstedt in northern Germany (12th c. BC) has been described as a trading post for people from Scandinavia and the Baltic Sea region, as well as a cult centre and seat of a ruling elite. Burials Associated with Nordic Bronze Age settlements are burial cairns, mounds and cemeteries, with interments including oak coffins and urn burials; other settlement associations include rock carvings, or bronze hoards in wetland sites. Some burial mounds are especially large and, with respect to the amount of gold and bronze in them, extraordinarily rich for this time period. Examples of prominent burial mounds include the Håga mound and Kivik King's Grave in Sweden, and the Lusehøj in Denmark. A minimum of 50,000 burial mounds were constructed between 1500 and 1150 BC in Denmark alone. Oak coffin burials dating from the 14th-13th centuries BC contained well-preserved mummified bodies, along with their clothing and burial goods. The bodies were intentionally mummified by watering the burial mounds to