It lies along State Route 56 , 30 miles ( 48 km ) west of Cedar City .
Newcastle ( also New Castle ) is an unincorporated community and census - designated place ( CDP ) in southwestern Iron County , Utah , United States .
Newcastle lies along State Route 56 , 30 miles ( 48 km ) west of Cedar City .
Newcastle ( also New Castle ) is an unincorporated community and census - designated place ( CDP ) in southwestern Iron County , Utah , United States .