Riddle

47.627503, -122.242104 (OpenStreetMap, Google Maps, Yandex Maps)

According to the wikimapia.org there is update summer residence of Mongolian emperor on Washington lake in town with Arabic name.
From place's description open wikipedia page
What's square footage of the building in feet?
66,000; 66000; 66 000

Present in routes of categories Online. Race, Online. Walk