You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.

Category: EUROPEAN DINING 
Clue: It's said the Witchery by the Castle, on Castle Hill in this Scottish city, is haunted by several ghosts
edinburgh

Category: COLLEGE SPORTS 
Clue: 2 college players have rushed for more than 2,300 yards in a season: Barry Sanders & this USC back, later a Raider
marcus allen

Category: LARGE EQUIPMENT 
Clue: For smooth travel, ballast tampers & ballast regulators keep the gravel at the right level among these

railroad tracks