La Seu, also known as the Cathedral of the Holy Cross and Saint Eulalia, is the Gothic cathedral in Barcelona. It is located in the Gothic Quarter of the city and is one of the most iconic landmarks in Barcelona. Construction of the cathedral started in the 13th century and was completed in the 15th century. It is dedicated to the co-patron saint of Barcelona, Saint Eulalia. The cathedral features stunning architecture, including intricate stained glass windows, tall spires, and a beautiful cloister. Inside, visitors can explore the nave, chapels, and the crypt where the remains of Saint Eulalia are kept. The cathedral is an important religious and cultural site in Barcelona, attracting both locals and tourists.