The area in front of it had over the centuries become choked with a maze of sheds and small shops that had grown up around its columns. These medieval accretions were cleared by order of Pope Eugenius IV (1431-39) and the piazza was laid out and paved. In the center of the piazza is a fountain, the Fontana del Pantheon, surmounted by an Egyptian obelisk. The fountain was constructed by Giacomo Della Porta under Pope Gregory XIII in 1575, and the obelisk was added to it in 1711 under Pope Clement XI. The surrounding buildings are 18th and 19th century.