Nottingham Castle was a castle in England. This castle was associated with Nottingham and Sherwood Forest in the tales of Robin Hood, a mythological leader of a band of outlaws in 12th century England. In the tales, this castle was the abode of the High Sheriff of Nottingham and his second-in-command Sir Guy of Gisbourne.
In 2367, the entity known as Q transported the senior officers of the USS Enterprise-D into a recreation of the 12th century setting and the story of Robin Hood in an attempt to teach Captain Picard a lesson about love. During the reenactment, Picard had to choose whether to let Maid Marian (Vash) die or risk his crew's lives trying to rescue her from Nottingham Castle. (TNG: "Qpid")