A key to understanding the Knap of Howar is that sea levels and, therefore, the shoreline have changed dramatically in the last five-six thousand years.The Knap would have been some distance from the sea, perhaps part of a larger settlement. Papay might still have been connected to Westray, its larger island neighbour at that time. 
The name 'Knap of Howar' means the 'knoll of mounds' and describes the sandy dunes which covered the remains before their first excavation by William Traill and William Kirkness in 1929. The combined action of wind and winter storms had revealed stonework and shell-packed midden (waste) which had been used to insulate the structure. They found two well-constructed, oval and inter-connected stone buildings or house structures. They thought the buildings dated from the iron age - at that time most neolithic structures were labelled 'Pict's Houses'.  

The remains were left until the 1970s when fresh excavations were undertaken and the ruins consolidated by the Ministry of Works (now Historic Scotland). Excavations were supervised by Anna Ritchie. Radiocarbon dating of finds from these excavations showed, remarkably, that the Knap of Howar had been lived in between 3700 and 2800BC. In fact. it was the oldest known inhabited structure in northern Europe!