Built in ' by the Spanish Viceroy 600, then passed to the Bourbons, the Savoy, then from 1946, the State, the Palace was for centuries the center of power; still on the piazza del Plebiscito (off old palace) overlooking the headquarters of the Military Command in Southern Italy and the prefecture. Currently the Palace houses the Museum of historic Apartment and the rich national library and is home to the Superintendence for architectural heritage, landscape, historical, artistic and ethno-anthropological heritage of Naples and province. The project was commissioned by Viceroy Fernando Ruiz de Castro to the architect Domenico Fontana (1543-1607), which improntò late-Renaissance fees. The original square body was enlarged a century later with the "new" Arm built by Charles of Bourbon, an L-shaped body stretched out towards the Castel Nuovo where currently houses the library. Ferdinand II of Bourbon, following a fire (1837), radical work that, under the guidance of the architect Gaetano Genovese, expanded the old factory, giving it an architectural impression. The Fountain the Mannerist façade long (nearly 170 m) with lower arches were later partly closed: in 1888 Umberto I had put in the eight niches statues of the King of Naples, the first of their respective dynasties (Ruggiero the Norman; Frederick II of Swabia; Charles I of Anjou; Alfonso I of Aragon; Charles V; Charles III of Bourbon; Joachim Murat; Vittorio Emanuele III) in order to represent the continuity of the Savoy dynasty in the history of Naples. From the courtyard of honor you access left to the Royal gardens, right in the Backyard of the Carriages and the Belvedere courtyard while the staircase of honor introduces the historical Apartments, set up as a museum. The gardens are located in an area always Green by rulers of Naples since the founding of Castelnuovo at the end of the 13th century, then settled to the Viceregal era Park with avenues, statues and "secret gardens" and surrounded by an iron railing with Golden-tipped lances, which opens from 1926, right in front of Castelnuovo, an entrance surrounded by iron statues of Grooms (known as "bronze horses") by Clodt Baron von Jurgenburg, gift of Tsar Nicholas I to Ferdinand II in memory of the visit of 1845. At the bottom of the ramp leads to the nineteenth-century Stables, now recovered for use espostivo.