1. Piazza Unità d'Italia: Trieste's main square, one of Europe's largest, boasting elegant architecture and stunning views of the Adriatic Sea.

2. Castello di Miramare: A picturesque castle perched on a cliff, offering panoramic vistas of the sea and surrounded by a beautiful park with gardens.

3. Cattedrale di San Giusto Martire: Trieste's grand cathedral featuring a mix of architectural styles, including Romanesque, Gothic, and Baroque.

4. Canale di Ponterosso: A charming canal lined with colorful buildings, cafes, and restaurants, providing a picturesque backdrop for leisurely strolls.

5. Museo Revoltella: A museum housed in a historic palace, showcasing a diverse collection of modern and contemporary art, including paintings and sculptures.

6. Teatro Romano: Ancient Roman Theater and ruins dating back to the 1st century AD, offering insights into Trieste's rich historical heritage.

7. Grotta Gigante: the largest single room cave in the world; the cave is large enough to fit St. Paul's Cathedral.

8. The churches: Trieste boasts an incredible array of churches that date back to its time as the largest Austrian-Hungarian port. Churches include Greek Orthodox, Serbian Orthodox, Catholic, Lutheran, Evangelican, and a Sinagogue.