Austria

Altfinstermünz
A medieval fortress over the River Inn near to the Austrian villages of Pfunds and Nauders. Built in 1472 as a crossing point linking Graubünden in Switzerland to the Austrian Tyrol, it was once used as a customs house on the old Roman trade route over the Reschenpass. A view inside one of the rooms can be seen here.
( Firefox users with old graphics cards may need to enable 'WebGL' ) See here
Flag of Austria