"Lights will guide you home..."

St Mary's lighthouse is one of the major landmarks of the Northumbrian coast.

It is located just to the north of Whitley Bay, reached by a causeway that is flooded at high tide - you can just see the start of the causeway in the picture.  The history of the light goes back many centuries before the current building (which is no longer maintained by Trinity House.)  The original light was maintained by monks.  It's not known when they first settled the island, but the first extant records go back to 1090, when Tynemouth Priory was reconstituted by the Norman Earl of Northumbria, Robert de Mowbray, as a cell of the Abbey of St Alban's. Shortly after that a chapel dedicated to St Helen was built on the site, and the monks kept a candle burning to warn ships of the dangers.  This became known as a "St Mary's Light", and in its turn this gave its name to the bay and the island.
The current building dates from 1898, and was intended to replace the Tynemouth lighthouse, which had been in service since 1664, and was located within Tynemouth Castle.  It was required partly because the light from the Tynemouth light was often obscured by smoke, but more urgently because the War Office wished to improve the defences of the Tyne Estuary: this was after all at the start of the naval rivalry between Britain and Germany which was one of the causes of the Great War.
The current Tynemouth lighthouse sits at the end of the northern jetty that protects the entrance to the Tyne: the earlier one was on the headland above the defences in the background.

On one of his visits to the North of England JMW Turner made sketches of the old castle with the lighthouse on the headland, which later became both a painting (in Blackburn Art Gallery) and was copied as an.engraving: as you can see the priory ruins haven't changed much since his time.