A small single-storey building of tooled granite rubble blocks with a hipped slate roof. It was pobably built c1860 as part of the continuing development of Porth Penrhyn, and the building is still in its original use as harbour master's office. It is listed as an integral feature of the remarkable late eighteenth and nineteenth-century industrial port complex at Porth Penrhyn, and the building has strong group value with the other structures here, in particular the Grade II* listed New Dock on the eastern quay of which it sits.

Source:- Cadw listed buildings, NJR 16/05/2011