Scandinavian Scotland Oronsay have produced important pagan Norse burial grounds. An 11th-century cross slab decorated with Irish and Ringerike Viking art on Islay was found in 1838. Rubha an Dùnain, today an uninhabited peninsula to the south of the Cuillin hills on Skye, contains the small Loch na h-Airde, which is connected to the sea by a short artificial canal. This loch was an important site for maritime activity for many centuries, spanning the Viking and later periods of Scottish clan rule. There is a stone-built quay and a system to maintain constant water levels. Boat timbers discovered there have been dated
Hills in the Puget Lowland as Lake Washington; and numerous kettle lakes, and Puget Sound itself. High points on the plateau remain, most of which are a drumlin (rocky glacial debris), or a bedrock intrusion that predated glaciation. Hills above 500 feet are considered exceptional. Hills are glacial deposits unless otherwise noted. King, Pierce and Snohomish Counties run up to the crest of the Cascades where their high points reside; therefore, the Cascades and attached foothills are excluded. Likewise for Thurston County in the Mount Rainier area, and Mason County's Olympic Mountains foothills. Landforms north of the Tacoma Narrows (Island, King, Kitsap, Pierce and Snohomish