Duino Castle (Italian: Castello di Duino, German: Schloss Duino, Slovene: Devinski grad) is a fourteenth-century fortification located in the village of Duino, located in the municipality of Duino-Aurisina, near Trieste, modern-day Italy, on the cliffs overlooking the Gulf of Trieste.
Building commenced in 1389 at the order of the Wallsee family. The ruins of an older castle built in the eleventh century by the Patriarch of Aquileia are located on the grounds. In the nineteenth century, it became one of two residences for Prince Alexander von Thurn und Taxis and his wife Princess Marie of the Czech branch of the House of Thurn und Taxis. While not the wealthiest of the Thurn und Taxis line, Alexander and Marie supported artists and writers, including Bohemian-Austrian poet Rainer Maria Rilke. While a guest of Princess Marie in early 1912, Rilke began to write his Duino Elegies, a collection of ten long, deeply philosophical and mystical poems which are considered to be his greatest work. Rilke dedicated his work to Princess Marie when they were completed in February 1922 and published the following year.
Duino Castle remains property of the Thurn und Taxis family, and is owned by Prince Alexander and Princess Marie's great-grandson, Prince Carlo Alessandro della Torre e Tasso, Duke of Castel Duino.
Most of the castle and its grounds have been opened to the public as a museum and park, while parts of the castle have housed the United World College of the Adriatic since 1982.