Knap of Howar, Scotland – around 3700 BC.
It is the oldest preserved stone house in north west Europe, located on the island of Papa Westray, Scotland. The name is Old Norse for `mound of mounds’ or `large barrow’. This ancient real estate consists of two structures, commonly referred to as `the farmstead’, built through dry stone construction with an adjoining passageway between them. Based upon archaeological excavations, it is thought that these structures were built on top of a much older site and formed the centre of a farming establishment.