Piazza Unità d'Italia is a large public square located in the historic center of Trieste, Italy. It is considered to be one of the most beautiful squares in Europe and is the largest seafront square in the world.

The square was originally built in the late 1800s after Trieste was annexed to Italy. It was designed by architect Giuseppe Bruni and was intended to be a symbol of the new Italian city. The square is surrounded by magnificent buildings, including the historic Palazzo del Municipio, the Palazzo Modello, the Palazzo Pitteri, the Palazzo Stratti, and the Palazzo della Regione. It is also flanked by two historic cafes, the Caffè degli Specchi and the Caffè Tergesteo.

At the center of the square stands the Fontana dei Quattro Continenti (Fountain of the Four Continents), which was designed by Giovanni Battista Mazzoleni in 1754. The fountain features four statues representing the four continents known at the time: Europe, Asia, Africa, and America.

Piazza Unità d'Italia is a popular gathering spot for locals and tourists alike. It offers stunning views of the Adriatic Sea and the surrounding hills, making it a great place to relax and take in the beauty of Trieste. The square also hosts many cultural events throughout the year, including concerts, markets, and festivals.