Sandby published an aquatint of Caernarvon Castle in 1776. It was probably derived from the same drawing as this watercolour.
A slightly larger version of 'Caernarvan Castle' was in the Arthur Russell Johnson Collection (sold at Christies's on 13 July 1965, Lot 153) and an oil version was sold at Bonhams on 2 July 1965, Lot 172. Both of these versions however have extended foregrounds compared to the Walker's view.