Buda Castle, the historic seat of the Hungarian kings in Budapest, dating from the 18th century, UNESCO World Heritage Site, Budapest, Hungary, Europe

Buda Castle dating from the 18th century, the historic seat of the Hungarian kings, UNESCO World Heritage Site, Budapest, Hungary, Europe

Interior decoration of the Moorish Salon where Hispanic and North-African elements are combined, Peles Castle, Sinaia, Romania, Europe

Carmarthen Castle, Carmarthenshire, Wales, United Kingdom, Europe

View of the Valentino Castle (Castello del Valentino), UNESCO World Heritage Site, situated in Parco del Valentino, the seat of the Architecture Faculty of the Polytechnic University of Turin, Turin, Piedmont, Italy, Europe

View of the Valentino Castle (Castello del Valentino), UNESCO World Heritage Site, situated in Parco del Valentino, the seat of the Architecture Faculty of the Polytechnic University of Turin, Turin, Piedmont, Italy, Europe

View of the Valentino Castle (Castello del Valentino), UNESCO World Heritage Site, situated in Parco del Valentino, the seat of the Architecture Faculty of the Polytechnic University of Turin, Turin, Piedmont, Italy, Europe

View of the Valentino Castle (Castello del Valentino), UNESCO World Heritage Site, situated in Parco del Valentino, the seat of the Architecture Faculty of the Polytechnic University of Turin, Turin, Piedmont, Italy, Europe

View of the Valentino Castle (Castello del Valentino), UNESCO World Heritage Site, situated in Parco del Valentino, the seat of the Architecture Faculty of the Polytechnic University of Turin, Turin, Piedmont, Italy, Europe

Hohenschwangau Castle and Alpenrose Hotel, Schwangau, Allgau, Schwaben, Bavaria, Germany, Europe

Narrow painted veranda with deep niches and carved stone chair assemblage, Kuchaman Fort, Rajasthan state, India, Asia

Inveraray Castle, the ancestral seat of the Dukes of Argyll, Inveraray, Argyll and Bute, Scotland, United Kingdom, Europe

Christian VI's Room, Rosenborg Castle, Copenhagen, Denmark, Scandinavia, Europe

Girls wearing tutus in blanket fort on sofa

Boys playing in pillow fort

Hohenzollern Castle, the ancestral seat of the House of Hohenzollern, photographed in the evening with the illuminated villages in the background

View of the Kremlin wall from the Alexander Garden side, Moscow, Russia

Konventsremter, Malbork Castle, formerly Marienburg Castle, the seat of the Grand Master of the Teutonic Knights, Malbork, Mazury, Poland, Europe

Morning mood with an angler on the Nogat River with Malbork Castle, formerly Marienburg Castle, the seat of the Grand Master of the Teutonic Knights, Malbork, Mazury, Poland, Europe

Malbork Castle, formerly Marienburg Castle, the seat of the Grand Master of the Teutonic Knights, Malbork, Mazury, Poland, Europe

Malbork Castle, formerly Marienburg Castle, the seat of the Grand Master of the Teutonic Knights, Malbork, Mazury, Poland, Europe

View of the Kremlin wall from the side of the Alexander Garden, Moscow, Russia

Malbork Castle, formerly Marienburg Castle, the seat of the Grand Master of the Teutonic Knights, Malbork, Mazury, Poland, Europe

Romantic Marksburg castle in Braubach, seat of the German Castle Association eV, DBV, UNESCO World Heritage Site Oberes Mittelrheintal Upper Middle Rhine Valley, Rhineland-Palatinate, Germany, Europe

Hunting lodge, Wasserburg Linn moated castle, museum, Krefeld, North Rhine-Westphalia, Germany, Europe

Fortress of Suceava, 1375; Suceava, Suceava County, Romania

Fortress of Suceava, 1375; Suceava, Suceava County, Romania

Fortress of Suceava, 1375; Suceava, Suceava County, Romania