The Cathedral of Trieste was built between 1302 and 1320 on two ancient churches. The bell tower was originally higher, but in 1422 it was struck by lightning and reduced to its present height. On the façade there is a huge rose window in karst stone. Inside, the two side apses are decorated with magnificent mosaics, the work of Venetian and Constantinopolitan workers.
The church of Sant'Antonio Taumaturgo or Sant'Antonio Nuovo was built between 1825 and 1849 on a former 18th century chapel. The famous neoclassical architect Pietro Nobile (1774-1854) was in charge of the construction of the building. On the main façade there are six statues sculpted by Francesco Bosa in 1842, representing St Just, St Sergius, St Servolo, St Maurus, St Euphemia and St Thecla.
The Church of the Holy Trinity and St. Spyridon is a Serbian Orthodox church built between 1868 and 1885. It is the work of the architect Carlo Maciachini (1869) and it stands on the site of a pre-existing church of 1753, also dedicated to St. Spyridon. The architecture is clearly of Byzantine taste and is characterized by a dome higher than the four bell towers. The façade is decorated with nine large statues by the Milanese sculptor Emilio Bisi (1850-1920). The interior is richly decorated according to Byzantine canons, entirely decorated with oil paintings imitating mosaics.