The National Art Museum of Catalonia, also known as MNAC, is a must-visit attraction in Plaza de España. This museum houses an extensive collection of Catalan art, spanning from the Romanesque period to the 20th century. Visitors can admire masterpieces by renowned artists such as Salvador Dalí, Joan Miró, and Antoni Gaudí. The museum's impressive architecture and panoramic views of Barcelona make it a favorite among art enthusiasts and history buffs.