works were continued in the 1920s by architect Adolfo Marques da Silva. In the 1940s, during Salazar's Estado Novo regime, the monumental stairway in front of the portico of the Parliament was completed. The stairway was designed by Cristino da Silva, who was also responsible for the project of the gardens in the back of the Palace. Since Portugal became a democracy after the 1974 Carnation Revolution the area in front of the palace has been the most popular location for demonstrations held in Lisbon. In 1994–1997 an annex building was constructed near the old Palace. This modern structure was designed by Fernando Távora and allowed for an expansion of the space of the Portuguese Assembly without altering its historical outlook. The Palace of Saint Benedict has been classified as a National Monument since 2002. Prime Minister's Residence Just behind the main building there is a mansion that serves as residence for the Prime Minister of Portugal. The mansion, dated from 1877, was built within the garden of the old monastery. It has been the Prime Minister's official residence since 1938, when Salazar moved in. References External links Virtual visit to the Palace in the official site of the Portuguese Parliament. Buildings and structures completed in 1938 Legislative buildings in Europe Seats of national legislatures Palaces in Lisbon National monuments in Lisbon District