Visiting the main square, the largest square in Europe with open access to the sea, is a must in Trieste. Don't be surprised if the architecture reminds you of Vienna. Trieste was part of Austria until 1918, and the elegant palaces are built in the same architectural style as the Viennese Ringstrasse.

High up on a hill, the Castello offers the best panoramic view over the rooftops of Trieste. The medieval castle from the 16th century has its roots in ancient Roman times. The castle museum showcases a beautiful weapons collection and offers interesting insights into the Roman and military history of the city.

The Cathedral of San Giusto in Trieste is located on the hill of the same name and is a beautiful example of Romanesque-Gothic architecture. The beautiful rose window and the impressive apse mosaics, depicting scenes from the lives of Christ and the Virgin Mary, make the church one of the city's most beautiful sights. You can also climb the bell tower for lovely views, but the view from the adjacent castle is much nicer.

The Molo Audace is a historic pier located on the sea shore of Trieste, just steps from Piazza Unità d'Italia and the Grand Canal. Originally constructed in the mid-18th century using the wreck of the Austrian vessel San Carlo, it has been extended over the years to its current length of 246 meters. Today, the pier serves as a popular spot for leisurely walks and offers stunning views of the seafront and the city. It is also a traditional meeting place for couples, who often share a kiss at the end of the pier.

The Canale Grande in Trieste, built in 1754, is small compared to Venice's famous canal at only 300 meters long, but still charming. Originally, it was intended for ships to sail directly into the city. Today, surrounded by historic buildings, the canal is a wonderful place for a stroll. The pedestrian bridge Passaggio Joyce is particularly popular for photos.

The Revoltella Museum, founded by Baron Pasquale Revoltella in 1872, showcases 19th and 20th-century art. Housed in a historic palace with a modern extension designed by Carlo Scarpa, the museum offers a wonderful collection of Italian and European masterpieces.

Risiera di San Sabba is a five-storey brick-built compound located in Trieste, northern Italy, that functioned during World War II as a Nazi concentration camp for the detention and killing of political prisoners, and a transit camp for Jews, most of whom were then deported to Auschwitz. SS members Odilo Globočnik and Karl Frenzel, and Ivan Marchenko are all said to have participated in the killings at this camp. The cremation facilities, the only ones built inside a concentration camp in Italy, were installed by Erwin Lambert, and were destroyed before the camp was liberated. Today, the former concentration camp operates as a civic museum.

Saint Spyridon Church is a Serbian Orthodox church in Trieste, Italy.

Piazza della Borsa, a significant square in Trieste, is a vibrant hub known as the city's "second living room." Once the economic center in the 19th century, it houses the neoclassical Old Stock Exchange and features notable landmarks like the Leopold I column and the Art Nouveau Bartoli house. Recently the square was pedestrianized. Since it's in the historic centre, you'll have no trouble seeing it on your way to/from the Canal Grande.

The Temple of Monte Grisa, officially the National Shrine of Mary Mother and Queen, is a Roman-Catholic church north of the city of Trieste. Located at an altitude of 300 metres on the edge of the Karst Plateau above Barcola and Miramare Castle, it is a most conspicuous landmark. It was built at the initiative of Antonio Santin, since 16 May 1938 Bishop of Trieste and Koper. Seeing the riots between the Nazi occupiers and the Comitato di Liberazione Nazionale on 30 April 1945 he made a vow to erect a church, if Trieste was saved from total destruction. The city was saved and in 1959 Santin obtained permission from Pope John XXIII to build a pilgrimage church dedicated to the Holy Mary as a symbol of the peace and unity of all people. The temple was designed by Professor Antonio Guacci, after sketches by Santin. The triangular structures should evoke the letter M as a symbol of the Holy Mary. The church was built in between 1963 and 1965, after a first stone had been laid on 19 September 1959. Santin inaugurated the church on 22 May 1966. On 1 May 1992 Pope John Paul II visited the temple. In 2010 restoration works took place, because the concrete had suffered from alkali-silica reaction.

The Synagogue of Trieste is a Jewish house of worship located in the city of Trieste, northern Italy.

The Arco di Riccardo is a Roman triumphal arch in Trieste, Italy. The 7.2 metre arch is the only remaining part of the city's Roman walls, constructed from 33–32 BC. Folk etymology credits the arch's name to Richard the Lionheart, the Crusader king of England, who is known to have been in the vicinity in the early 1190s. However, there is more evidence that its current name is a corruption of Arco del Cardo, with a cardo being the main north-to-south route in Roman cities. Another hypothesis is that the name is corrupted from Arco del Ricario, with Ricario being a nearby medieval courthouse. Throughout the Middle Ages, the arch remained mostly visible, though sometimes incorporated into buildings. Its western side was fully excavated in 1913, though the eastern one remains incorporated into a modern building.

Trieste City Hall is the seat of the city and commune of Trieste in Italy.

The Church of Sant'Antonio Taumaturgo, is the main religious building in the Borgo Teresiano in the centre of Trieste as well as the city's largest Catholic church. It stands on a square also known as Sant’Antonio Nuovo, at the end of the Grand Canal. The building project dates back to 1808, but work only began in 1825. The church has a facade of ionic columns with six statues sculpted by Francesco Bosa in 1842, representing Saint Justus, Saints Sergius and Bacchus, Saint Servulus, Saint Maurus, Saint Euphemia and Saint Tecla.

Politeama Rossetti is an Italian theatre situated in the city of Trieste. With over 60 shows scheduled each season, running from October to June, its stage shows include plays, musicals, ballet, dance and rock concerts. It is the home of Teatro Stabile del Friuli Venezia Giulia, one of Italy's major public theatres. The artistic director is Antonio Calenda. The theatre was built in 1878 and designed by Nicolò Bruno. It was heavily restored in 1928, 1969 and 1999. While the original capacity was over 5,000, it can now sit 1,531. In the recent years the theatre has specialised in the presentation of major West End and Broadway musicals, including the original productions of Cats in 2008, Mamma Mia!, The Rocky Horror Show and Chicago in 2009. In 2010 the theatre staged We Will Rock You, featuring the music of Queen, the acclaimed 50th anniversary production of West Side Story and Andrew Lloyd Webber’s Evita. In 2011 the theatre hosted the Italian premieres of the musicals Chess and Spamalot.

The Teatro Lirico Giuseppe Verdi, situated in the heart of Trieste, is a historic opera house named after the renowned composer Giuseppe Verdi. It was designed by Gian Antonio Selva, the architect of Venice's La Fenice and inaugurated in 1801. The theatre boasts a stunning horseshoe-shaped auditorium and blends the interior elegance of La Fenice with the exterior grandeur of Milan's La Scala. With its own resident orchestra and choral ensembles, the Teatro Verdi offers a rich program of opera and musical performances, including the famous International Festival of Operetta every summer.

The Lighthouse of Victory (Faro della Vittoria) in Trieste is a remarkable monument built between 1923 and 1927 by architect Arduino Berlam. It serves a dual purpose as both a navigational aid, illuminating the Gulf of Trieste, and a commemorative monument honoring fallen sailors of World War I. Located on Poggio di Gretta, 60 meters above sea level, it features a majestic bronze statue of winged Victoria and an imposing column topped with a lantern. Visitors can explore the first terrace of this historic lighthouse, which offers fantastic panoramic views of the surrounding area.

Kleines Berlin, or 'Little Berlin,' is a fascinating underground complex of World War II air-raid tunnels in Trieste. Managed by passionate volunteers, tours are available every last Friday of the month, though special arrangements can be made. For only 5 EUR, visitors can explore these historically rich tunnels, learning about Trieste's wartime history, German occupation, and speleology. The tunnels were constructed by the Germans after annexing Trieste in 1943, using three different companies to ensure secrecy. They served as an air-raid shelter for German soldiers and civil employees, with separate sectors for Italian and German use. This unique experience is highly recommended for history enthusiasts.

The Trieste Campo Marzio Railway Museum is a museum in Trieste, concerned with railway and tram transportation. It is housed in Trieste Campo Marzio railway station, the former Trieste Staatsbahnhof during the Austro-Hungarian period and one of the two main terminal stations in Trieste. the museum has been closed for renovation by the Fondazione FS.

The Church of the Immaculate Conception of the Blessed Virgin Mary, better known as the Church of Santa Maria Maggiore, and also known as the Baroque church of the Jesuits, is a religious building located in Trieste, in the province and diocese of Trieste; it is the seat of a parish included in the deanery of San Giusto Martire. The Baroque church was built in the 17th century by the Jesuit company and has been managed by the Franciscan friars since 1922. The church is located in via del Collegio, at the foot of the San Giusto hill and near the Basilica of Cristo Salvatore, in the immediate vicinity of the historic center of Trieste.

The Greek Orthodox Church of San Nicolò dei Greci, Trieste, Italy, is a historical Greek Orthodox Church built in 1784-1787 and re designed by architect Matteo Pertsch. The building is also known as the Greek Orthodox Church of San Nicholas and Most Holy Trinity. The iconostasis was painted by Spyridon Sperantzas

Piazza Venezia is one of the best known squares of Trieste, the capital of Friuli Venezia Giulia, Italy. The square has a view over the Adriatic to the Alps with the Dolomite Mountains Civetta, Monte Pelmo and Antelao. The square is known for its central monument and its prominent buildings and their features: the Revoltella Palace designed by Friedrich Hitzig, with its furnishings and art collection, today including over 350 pieces, the historic Mizzan pharmacy, still conserving the original furnishing, with carved boiserie and fire-worked stained glass windows with mythological images, and the monument of Maximilian I of Mexico, the work of sculptor Johannes Schilling. The square is connected to via Torino, often credited as the center of Trieste's nightlife.

The Civico Museo Sartorio is a museum in Trieste, northern Italy. Set in an urban villa, it exhibits ceramics, majolica, porcelain and pictures, typical equipment of Trieste's villas at the end of the 19th century. Besides the villa itself being a very interesting building architecturally, it contains drawings of Giambattista Tiepolo, painting of Giambattista Pittoni and a glyptotheque. The museum opened to the public partially in 1949 and completely 1954. In 2006, the museum reopened after a period of renovation. Currently the Museum hosts temporary exhibits and cultural events such as theatre and music in the summer.

The Church of San Pasquale Baylón in Trieste is a charming Neo-Romanesque church located on the hill of Chiadino, nestled within the lush Revoltella Park. Built between 1863 and 1866, it features a Greek cross plan and a crypt housing the sarcophagi of Baron Pasquale Revoltella and his mother. The park's greenery and vibrant flowers make it a picturesque spot, often chosen for wedding ceremonies.

Civico Museo di Storia Naturale di Trieste is a natural history museum in Trieste, northern Italy. It contains several collections, including more than two millions botanical, zoological, mineralogical, geological, and paleontological specimens.

The Civico Orto Botanico di Trieste is a municipal botanical garden located at via Marchesetti 2, Trieste, Friuli Venezia Giulia, Italy. The garden was established in 1842 when the city first experimented with plantations of the Austrian black pine. By 1861 a botanical garden began to take shape with species collected from the Julian Alps in Istria and Dalmatia. In 1873 it opened to the public, in 1877 published its first catalog of 254 plants, and in 1903 became a public institution attached to the Museum of Natural History. In 1986 the garden was forced to close to the public for lack of resources, but in 2001 part of the garden reopened. Today the garden includes several sections, including one devoted to the natural flora of Carso, Trieste, Istria, and adjacent territories. Other sections include historic flower beds, poisonous plants, ornamental plants, plants magical, garden of simples, lotus flowers, food plants, formal garden, dyeing plants, and useful plants. It also contains greenhouses.

The Jewish Museum “Carlo and Vera Wagner, is located in via del Monte 5/7, Trieste, Italy. It was inaugurated in 1993, by the initiative of Mario Stock together with the generous support of the Wagner-de Polo family.