Trogir, Croatia, is a UNESCO World Heritage Site and is known for its medieval architecture and historical sights. Historical sites worth visiting in Trogir include St. Lawrence Cathedral, Kamerlengo Fortress, City Loggia, St. Nicholas Monastery Complex and Duke's Palace. These sites offer a glimpse into Trogir's rich history and culture, with impressive examples of Gothic, Renaissance and Baroque architecture and art. Visitors can also explore the narrow streets of the old town and discover hidden gems in the charming city.