Alderney Lighthouse, Lighthouse on the northeast coast of Alderney, Guernsey

Alderney Lighthouse is a 32-metre granite tower on the north-east coast of Alderney, near Fort Les Hommeaux Florains. Its lantern sits 37 metres above high water. The 1912 lens sends four flashes every 15 seconds; since 2011 a pair of LED lamps on the tower sides provides the light.

Alderney Lighthouse was built from granite in 1912 under the guidance of local businessman William Baron, at a cost of £22,000, to warn ships off the Alderney Race and the rocks around the island. Earlier wrecks off Alderney, including the Leros, had shown the need for a light. It was electrified in 1976 and automated in 1997, when the last keepers left on 1 October.

Guided tours of the tower are given by local guides Anne and John Beaman, who show visitors the 1912 lens that still sends four flashes every fifteen seconds. The lighthouse is linked to the rest of Alderney by the Alderney Railway during the summer months, when tours run.

Guided tours run in summer, led by local guides Anne and John Beaman, when the Alderney Railway links the lighthouse to the rest of the island. Otherwise reach it by car towards Saye Beach and on along the coast road. The tower stands near Fort Les Hommeaux Florains, beside the strong Alderney Race current.

The 1912 lens still sends four flashes every fifteen seconds, though since March 2011 it is shrouded and the pulse comes from a pair of LED lamps fixed to the tower's sides. The same downgrade cut the range from 23 to 12 nautical miles and silenced the fog signal. The optic floats in a mercury bath on 16 supports, the mercury renewed every five years.