You can walk up to San Giusto Castle from downtown, or you can take the free elevator that brings you up the hill from inside the Park San Giusto parking garage. Since Trieste was in possession of the Habsburg family for nearly 800 years, it’s not surprising that they also built the Castello San Giusto between 1468 and 1636. It’s worth walking along the bastions, from where you can see the entire city – it’s truly an experience. The castle has a café, restrooms, an armory, and a Lapidarium (stone collection) where you can see Roman-era mosaics and sculptures from the surrounding area. In summer, concerts are held in the castle courtyard, and in spring and autumn, it’s worth visiting for the wine festival. You can check the entrance tickets and opening hours here.
