South Stack Lighthouse

IALA Heritage Lighthouse of the Year 2023 Nominee

Location: WALES - Anglesey. South Stack.

Lighthouse Operator: Trinity House

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Source: (photos as submitted to accompany nomination form by Trinity House 2023)

Lighthouse Description and History

(Text extracted from nomination form submitted by Trinity House 2023)

South Stack Lighthouse was first envisaged in 1665 when a petition for a patent to erect the lighthouse was presented to Charles II. The patent was not granted and it was not until 9 February 1809 that the first light appeared to mark the rock. The lighthouse was designed by Trinity House surveyor Daniel Alexander and originally fitted with Argand oil lamps and reflectors. Around 1840 a ‘railway’ was installed by means of which a lantern with a subsidiary light could be lowered down the cliff to sea level when fog obscured the main light.

In the mid 1870s the lantern and lighting apparatus was replaced by a new lantern. In 1909 an early form of incandescent light was installed and in 1927 this was replaced by a more modern form of incandescent mantle burner. The station was electrified in 1938.

On 12 September 1984 the lighthouse was automated and the keepers withdrawn. The lighthouse is now monitored and controlled from Trinity House’s Planning Centre in Harwich, Essex.

Reason For Nomination

(Text extracted from nomination form submitted by Trinity House 2023)

Intrinsic Heritage Interest of the Lighthouse

Construction and architecture

Trinity House built South Stack Lighthouse in 1809, upon the summit of a small island north-west of Holy Island in Anglesey, North Wales.

Trinity House appointed their Surveyor, Daniel Asher Alexander as the project’s architect. As well as working for Trinity House, Daniel Asher Alexander (1768-1846) also held the post of surveyor to the London Dock Company between 1796 and 1831. The lighthouse at South Stack was to be the first he designed; during the course of his career he became responsible for several others, including those at Inner Farne, Heligoland, Hurst, Harwich and Lundy Island.

During the building works, the unbridged gap between Holy Island and South Stack Island was traversed by an aerial ropeway with underhanging baskets and a primitive rope bridge, carrying people and building materials. One visitor to the construction site reported that a workman on the island once received news that his mother was unwell, but was unable to leave due to the lack of a boat. Desperate to see his ill mother, he crossed the aerial ropeway by hanging underneath, using his hands and legs to pull himself along. He made it safely across the chasm, to the cheers of his fellow workers, although was reprimanded by his supervisors, and afterwards all workers were warned never to emulate his feat.

The light was first officially shown at South Stack on Thursday, 9 February 1809, a mere nine months after work was started. The light came from 21 oil lamps with revolving reflective (‘parabolic’) dishes made of brass and lined with silver. There were seven dishes on each side of a triangular frame, which rotated by clockwork to create a light character of one white flash every two minutes.

Two separate dwellings were built to house the two keepers and their families. Another small building provided office space for Captain Evans (Agent for South Stack Lighthouse and as Collector of Light Dues at Holyhead) when he was present at the lighthouse. The three buildings were again rubble built using local undressed stone and had slate roofs. All buildings, including their roofs, were limewashed each year.

In 1828, Trinity House built a suspension bridge, and this was succeeded in later years by a rigid tubular lattice bridge – although the original towers of the suspension bridge have been retained to this day.

Getting to the bridge requires visitors to descend 400 stone steps down the cliff face, past visible strata of pre-Cambrian rock.

In 1874 the original tower was heightened to its current build, a simple white-painted tower with adjacent dwellings, and the lantern and lighting apparatus was replaced by a new lantern and a 1st Order catadioptric lens was installed (the same one in use today), rotated by means of a weight driven clock. The lighthouse keeper dwellings have since been converted to allow for tourism.

The site had two unusual features: an inverted fog-bell weighing 2.5 tons and an ingenious arrangement whereby, when fog or low cloud obscured the light, a small clockwork-operated lantern mounted on wheels was lowered down a railed incline—cut into the north side of the rock in 1832—to within 15.2m of the sea. Only the bed of the incline survives today.

In 1909 an early form of incandescent light was installed, which was upgraded in 1924. In 1938 the station was electrified for the provision of a fog signal and in 1964 electricity was extended to the lighthouse to power a 3½ kW 100 V electric filament lamp.

Cultural impact and associations

Since 1809, the dramatic and picturesque situation of the lighthouse—set against the spectacular cliffside steps—has attracted the attention of countless photographers, geologists, bird watchers, tourists and artists.

The station is regularly one of the most-submitted lighthouses in Trinity House’s annual photography competition, and also receives a considerable number of filming enquiries from TV and movie production companies.


South Stack Lighthouse is an active aid to navigation owned and operated by Trinity House; as such, Trinity House works hard to keep the building—and all of its aid to navigation systems—in good working order at all times.

Evidence of the site’s evolution over the ages can be seen throughout the site – former keepers’ cottages, the base of the old fog bell, the towers of the old suspension bridge, the include of the old low light railway, the walled access to the former second low light all help tell the story of this site – but also of broader developments in lighthouse technology over the years.

The lighthouse and its associated structures are protected as nationally listed buildings.

Public Access and Education

South Stack Lighthouse is one of the stations that Trinity House opens to the public for general access, in collaboration with a local community operator. Visitors may tour the former lighthouse engine room before climbing to the top of the lighthouse. South Stack is a wonderful place to watch thousands of breeding seabirds including guillemots, razorbills and puffins.

Trinity House continues to use its various channels for corporate communication (including its website and bi-annual journal Flash, as well as social media) to help inform and educate the public (among other stakeholders and interested parties) about the history of its lighthouses and the wider importance of marine aids to navigation.