Nürburg (German pronunciation: [ˈnʏɐ̯bʊɐ̯k]) is a town in the German district of Ahrweiler, in the state of Rhineland-Palatinate. It is also the name of the local castle, Nürburg Castle, which was built in the High Middle Ages. The name is derived from the Latin word "niger" which means 'black' (cf. French "noir" meaning the same), and burg which means "castle". The castle is made of basalt which usually has black color. The town is best known for its famous 24 kilometer race track, the Nürburgring. Five kilometers (3.1 miles) of the track are used for a Formula One grand prix.