Nottingham Castle, Nottingham, is located in a commanding position known as "Castle Rock". In the Middle Ages it was a major royal fortress and occasional royal residence. In decline by the 16th century, it was largely demolished in 1649, but sufficient fragments remain to give an impression of the layout of the site. A ducal mansion later occupied the summit of the promontory. This was burnt out by rioters in 1831, and later adapted as an art gallery and museum, which remains in use today.