It has been standing for almost 700 years. Begun by Jaume II in 1300 and built by Pere Salva, the architect of the Almudaina Palace, it is unique among Spanish castles in being entirely round. Three large towers surround a central courtyard, connected by an arch to a free standing keep. The courtyard itself is on two levels, the ground floor with semicircular arches and a flat roof, the upper level with Gothic arches and rib-vaulting. For the full effect, walk around the moat then climb onto the roof and look down into the courtyard to compare the contrasting styles. While you are there, look out over the city and the bay for one of the best views in Palma (Bellver meant 'lovely view' in ancient Catalan).
For many centuries the castle was used as a prison; Jaume III's widow and sons were imprisoned here for most of their lives. These days it contains Palma's museum of municipal history which traces the development of the city through its artifacts, with pottery from Talaiotic, Roman, Arab and Spanish periods.
You can get there by car or taxi, or take a bus to Plaza Gomila and climb up through the pine woods above Carrer de Bellver, passing a chapel on the way.