My pick
My tip“Right beside the cathedral; closed on Mondays, and the audio guide is good.”
The palace of the Muslim governors of the island. Its name comes from the Arabic “al-Mudayna” (the citadel). The island was Muslim from its conquest under the Umayyad Amir Abd Allah (902 CE), through the Taifa, Almoravid, Banu Ghaniya and Almohad periods, until Jaume I took it in 1229 CE and turned the palace into a Gothic royal residence, which is still an official seat.
Address
Carrer del Palau Reial, s/n