Llanddwyn Island is situated near the southern entrance to the Menai Strait. As a result it became important as shipping of slate from the ports of Bangor, Caernarfon and Felinhelli increased.
A beacon, called Tŵr Bach, was built at the tip of the island to provide guidance to ships heading for the Strait.
Another more effective lighthouse, Tŵr Mawr, which was modelled on the windmills of Anglesey, was built nearby in 1845.
My shot shows the Tŵr Mawr lighthouse with Snowdonia in the background.