beautiful landscape with aggstein castle ruin and danube river in wachau, austria

aerial aggstein alps ancient architectural architecture austria austrian beautiful building burgruine countryside culture danube destination donau europe european evening famous forest fortification fortress green high hill hills historic historical history krems landmark landscape lower medieval melk mountain nature old panorama panoramic picturesque river rocks rolling romantic ruin rural scene scenic sky stone sunset tourism tourist touristic tower town travel trees valley view wachau wall water