Work on the Royal Palace started in 1600, under the rule of the Spanish viceroys, by Neapolitan architect Domenico Fontana. The bulk of the palazzo was completed in two years, although a number of features (such as the staircase) were added 50 years later. The Bourbon monarchs had the building extended eastwards in the mid 18th century, when niches were added to the façade. Under French rule in the early 19th century, the interior took on its current neoclassical appearance, and the hanging gardens and statues of Naples' kings were added later that century.
The ticket office is on the left-hand side of the portico that skirts Piazza del Plebescito, with access to the 30 royal apartments through the well-appointed bookshop. The apartments, overwhelming in size and number, house a collection of paintings (interesting for their portrayal of Neapolitan rulers and customs), frescoes, tapestries, chandeliers and furniture from the 17th to the 19th centuries. The gilt-and-stucco ceilings are impressive, as is the gloriously ornate Teatrino di Corte (1768), a private theatre. The pleasant roof garden features flowerbeds, fountains and neoclassical benches.
The Palazzo Reale also houses the Biblioteca Nazionale (081 781 9111, www.bnnonline.it) national library, with its grand reading rooms and collections of manuscripts and musty books, some dating to the fifth century. There's also a tourist office just off the Cortile d'Onore, open on weekdays only and stocked with excellent leaflets for a number of sites and events in Naples. The gardens within the palace complex, dotted with modern sculpture, offer a quieter alternative to the nearby Giardini Publici.