The Gail river Valley (Slovenian: Zilja, Italian: Zeglia) is located in southern Austria (geographic coordinates: 46°43′39.40″N, 12°30′32.33″E, Elevation 1628 m; 46°36′23.10″N, 13 °53′11.84″E, Elevation 488 m). The source of the river Gail is located east of the Kartitsch saddle and the Puster valley in the Tyrolean municipality of Obertilliach. The river flows from west to east through the Southern Limestone Alps, between the Gailtal Alps in the north and the Carnian Alps in the south. The river reaches Carinthia in Lesachtal and from Kötschach-Mauthen flows down the wider Gail valley (German: Gailtal) with its steep slopes, parallel to the borders with Italy and Slovenia. Beyond its confluence with the Slizza (Gailitz) tributary in Arnoldstein, the Gail joins the Drava below the western Karavanke mountain range near the village of Maria Gail, part of the town of Villach. In general, the Alps can be said to be the 'mother of Europe', its largest and most significant natural resource that generated the rest of Europe's goods. The Gail Valley is located at the border between the Germanic, Romanic and Slavic civilizations and cultures, so it is an extremely complex, dynamic and controversial area and as such is attractive (for the author of this paper) for the study of Architectural Spatial Definition (ADS).