[4] The cupola, which is stone-clad around a steel frame that was constructed in the United States, is set planimetrically forward on the building to allow for the apse that contains La Republica, the "Statue of the Republic".

According to Eugenio Rayneri Piedra, the inspiration for the cupola came from the Panthéon in Paris by way of Bramante's Tempietto in San Pietro in Montorio.

[citation needed] The 56 steps leading to the main entrance, La Escalinata, is flanked by 6.5 m (21 ft) statues by the Italian artist Angelo Zanelli.

A Creole Cuban, Lily Valty served as the model for the body for Zanelli, and the inspiration for the statue came from Athena, the Greek goddess of wisdom.

[citation needed] Embedded in the floor in the center of the main hall is a replica 25 carat (5 g) diamond, which marks Kilometre Zero for Cuba.

The original diamond, said to have belonged to Tsar Nicholas II of Russia and have been sold to the Cuban state by a Turkish merchant, was stolen on 25 March 1946 and mysteriously returned to the President, Ramón Grau San Martín, on 2 June 1947.

The north patio features another statue The Rebellious Angel (El Ángel Rebelde) which was donated to the building after the inauguration.

[citation needed] On both sides of the end of the staircase are two bronze sculptural groups with granite pedestal by the Italian Angelo Zanelli, one male, and the other female, have a height of 6.70 meters and represent the first progress of human activity and the second the tutelary virtue of the people.

It was sculpted by Angelo Zanelli, author of the Altare della Patria, part of the monument to King Victor Emmanuel II, in Rome.