Vorarlberg is the westernmost federal state (Bundesland) of Austria. Although it has the second-smallest area (Vienna is the smallest) and population (Burgenland is less populated), it has the second-highest population density (after Vienna). It borders three countries: Germany (Bavaria and Baden-Württemberg via Lake Constance), Switzerland (Graubünden and St. Gallen) and Liechtenstein. The only Austrian state that shares a border with Vorarlberg is Tyrol to the east.