The National Pantheon, located in the historic area of Santa Clara, occupies the building originally intended for the church of Santa Engrácia, hosting the tombs of large figures of Portuguese history. Founded in the second half of the 16th century, the building was completely rebuilt in the late 1600s by architect João Antunes; although never open to worship, it retains, under the modern dome, the majestic space of the nave, animated by the decoration of colorful marbles, characteristic of Portuguese Baroque architecture. A reference element in the city's profile and offering privileged views of the city's historic area and the Tagus River, it is classified as a National Monument. In its vicinity is held weekly, on Tuesdays and Saturdays, the traditional Flea Market.