The Alba Carolina Fortress is a star-shaped fortress located in Alba Iulia, Romania. Built between 1714 and 1738, it was designed by the Italian architect Giovanni Morando Visconti as a military stronghold for the Habsburg Empire. The fortress covers an area of about 103 hectares and features impressive walls, bastions, and gates, showcasing the Vauban style of fortification. Today, the fortress is a significant historical site and a popular tourist attraction. Visitors can explore its well-preserved structures, including the Union Hall, the Roman Catholic Cathedral, and the National Union Museum. The fortress also hosts various cultural events throughout the year.