Noltland Castle is a mid to late 16th century stone Z-plan tower house, probably founded but then left unfinished by Gilbert Balfour of Westray. Standing on the site of an early 15th century castle, founded by Thomas Tulloch, Bishop of Orkney, the main block of the artillery-defended tower house is of four storeys and an attic. One of the opposing square angle towers is of five storeys, plus a garret and an adjoining courtyard with a later L-plan range of buildings also survives. The castle was held by Cromwell's troops in the mid 17th century, damaged by fire in 1746 and abandoned in the mid to late 18th century.