The building where this museum is sited used to be part of the old Palace of the Buen Retiro (17th century). It holds a collection of objects that illustrate Spanish military history. Among them there are a number of arms, like for example the sword of Boabdil, Granada's last Muslim king, or the Tizona, the sword that belonged to El Cid. You can also look at trophies, uniforms, models and army miniatures.