Castillo de la Peña de Ayllón, also known as the Fortaleza de Uncastillo, is a monumental medieval fortress dating from the eleventh to thirteenth centuries, built on a dramatic rocky outcropping. The oval-shaped structure measures approximately 115 by 75 meters and comprises two distinctive zones with the celebrated Torre del Homenaje (keep tower) rising prominently from the thirteenth century, featuring interior fireplaces and commanding views from its crenellated crown. The slender Torre de Vigía (watchtower) displays semi-octagonal architecture and housed a fourteenth-century Gothic palace with an interior spiral staircase. The keep now houses an interactive museum spanning three floors, featuring audiovisual presentations about the fortress's evolution, construction techniques, historical models, medieval weapons, and panoramic views from the terrace overlooking the town and surrounding landscape.
