["< sod > the'''blue valley mountain quarry'''( first section introduced in'' [ [ blue mountain mystery ] ]'' ) is a large disused slate quarry, located independently on each one of the narrow gauge lines of the adjacent skarloey railway. < eod > < sod > the'''blue mountain quarry'''( first introduced in'' [ [ blue mountain hill mystery ] ]'' ) is a large slate quarry, located adjacent on one another of the narrow gauge lines of the skarloey railway. it is also served by both a standard gauge branch line that breaches of the peel godred line. < eod >"]