Castle of Sanluri, Medieval castle in Sanluri, Italy.

The Castle of Sanluri, also called Eleonora d'Arborea's Castle, is a fortified building of the giudicale era in Sanluri, southern Sardinia. Its rough light tan and beige stone facade rises to a tall central block topped by a crenellated tower with squared merlons. Small arched windows and a rounded arched doorway with a dark wooden door open onto the front, where a vertical panel reads "CASTELLO".

The castle dates to the late 1100s, when it was built to mark and defend the border between two rival territories on the island. In 1409, a decisive battle nearby ended with an Aragonese victory that secured their control over Sardinia.

The castle is also called after Eleonora d'Arborea, though no document proves she stayed here; a chair said to have belonged to her is shown. The halls hold the Museo risorgimentale Duca d'Aosta, with the tricolour flag raised first in Trieste on 3 November 1918 and the original text of the Bollettino della Vittoria.

The main entrance opens onto the courtyard, from which stairs lead up to the museum rooms on the upper floors. The floors and steps can be uneven in places, so sturdy footwear makes the visit more comfortable.

Of the roughly 90 medieval fortresses once scattered across Sardinia, this is the only one still used as a private home while remaining open to the public. The family that owns it has built up the museum collections over generations, adding personal and local items over time.