The Old Cathedral of Coimbra, known as Sé Velha, is a Romanesque church located in the city of Coimbra, Portugal. Built in the late 12th century, it served as the main cathedral of the city and is one of the most important historical monuments in the region. Its robust architecture features thick walls, a fortified appearance, and a beautiful interior with intricate altarpieces. The cathedral is notable for its stunning cloister, which showcases Gothic elements, and its impressive main altar. It has been classified as a National Monument since 1910 and remains a significant site for both religious and cultural events in Coimbra.