A star-shaped fortress at the top of the Vomero hill, dominating the city's skyline. Built by the Spanish viceroys in the sixteenth century using the local yellow tufa, the castle served as the main military stronghold of the city for centuries and has been used as a prison, an administrative building, and a barracks. Today it functions as a cultural space hosting exhibitions.
The main reason to climb up — besides the exhibitions — is the view. From the ramparts you can see the entire bay of Naples in one sweep: Vesuvius to the east, the islands of Capri and Ischia to the south, the Phlegraean Fields to the west, and the city spread below. The view is better than from any other point in the urban area. Take the Centrale funicular from Via Toledo, or the Metro Line 1 to Vanvitelli.