Duino/Devin boasts two castles. The new castle is clearly visible from afar, but the old one survives only as a ruin. The new Duino castle reigns on the edge of a karst cliff which picturesquely rises above the sea. It is very well preserved, since in the course of centuries it has undergone numerous extensions, renovations and restorations. A visit to the castle offers a survey of the history of this area, and from its windows and terraces unique views over the Trieste Gulf are afforded. The oldest written source about the present castle dates from 1363 when it was separated from the older castle. The history of the castle is closely related to the Thurn und Taxis (Torre e Tasso) family. During World War I, Duino was practically part of the Austro-Hungarian first line of defence as its southernmost point.
The castle can now be a point of departure for a walk along the Rilke Trail. The about two kilometres long footpath runs along the edge of high cliffs above the gulf of Sistiana/Sesljan.