The architecture of Scotland in the prehistoric era includes all human building within the modern borders of Scotland, before the arrival of the Romans in Britain in the first century BCE. Stone Age settlers began to build in wood in what is now Scotland from at least 8,000 years ago. The first permanent houses of stone were constructed around 6,000 years ago, as at Knap of Howar, Orkney and settlements like Skara Brae. There are also large numbers of chambered tombs and cairns from this era, particularly in the west and north. In the south and east there are earthen barrows, often linked to timber monuments of which only remnants remain. Related structures include bank barrows, cursus monuments, mortuary enclosures and timber halls. From the Bronze Age there are fewer new buildings, but t