The Skerries Lighthouse is located 3km off the north coast of Anglesey on a set of low lying islets of the same name. The site comprises the lighthouse tower with attached keepers' accommodation, additional buildings including former engine house and secondary sector-light tower, the original lighthouse keepers cottage, and a well house. A single walled-garden survives, the other have been built over by a helipad. The landing places for supplying the lighthouse were connected by narrow gauge railway. The harbour facilities included unloading hooks suspended from pulleys operating on a wire ropeway (the Blondin system).

The facility has an unusual plan, in that it was built against the slope of the rock and the main entrance to the lighthouse is via a spinal corridor bisecting the accommodation block. The design includes well-protected cobbled yards for the castellated dwellings which had symmetrically sited privies with decorated doors, a garden, a stone bridge connecting two islets and the unique stone well-head building which may date from William Trench's early deign. Ancillary buildings associated with the establishment of a fog station, including an engine house, were added to the tower in the later 19th century, and a secondary circular tower adjoins the main tower to the southwest was added in 1903-4 to provide a red sector light.

The former engine house is a standard late 19th century Trinity house pattern, circular with recessed mullioned and transomed windows, with raked back upper lights; moulded cornice and blocking course. It has now been converted to Keepers' accommodation, and the square tower of the fog station adjoins this building to the north. This was probably originally the lobby of the engine house, raised in height on conversion to fog station. The original circular lobby at the head of stairs leading from the main entrance in the former accommodation block has 2-centred arched doorway with Trinity House arms over it in its north elevation. 

The central entrance to the main building gives access to a grand staircase leading directly to the lighthouse, separating the two keepers' dwellings (now amalgamated as one and linked at basement level). Each of these dwellings has two rooms on each floor, with rear wall fireplaces in rear rooms, corner fireplaces to front. The lighthouse tower has ground and first floor store rooms with stone slab ceilings. There is an open stone stairway beyond these with a plain cast iron rail. There are service rooms in upper stage, with a cast-iron tube (formerly housing weights for clock-work rotary mechanism for light) and the ladder stair to lantern.

The lighthouse itself is a tapering circular tower 22m high, on a tooled plinth, ashlar with tooled cornice defining a second stage. It is currently painted in three broad bands - white, red white. The tower has deeply recessed windows in upper stage, in lugged architraves. The solid stone crenellated parapet is corbelled out on moulded bracket. The sector-light tower to southwest is a battered circular stone tower with lattice-glazed cast-iron lantern with cast-iron rail to gridded platform. It is finished with lined-out render. Access is via an improvised landing from the main tower. More recently, fog signals have been built concentrically around the tower 

The cast iron lantern is continuously glazed with horizontal grid glazing bars. A drawing (No.1785) of it dated 1843 is held within the Trinity House Archive and titled 'Skerries Lighthouse, New Lantern'. The 1843 drawing has an additional notation that the lens is in 8-panels, by Wilkins, 1844, suggesting the lens was installed after 1844. Hague (1994: 50) records the ball-finial shown in the 1843 drawing as dating to 1848, which may indicate the date of the lantern being installed, following the purchase of the lighthouse by Trinity House in 1844 (below). Further annotation on Drawing 1785 records the addition of a 6-wick burner being fitted to the lamp within the lens, in 1876.

The lens and light were replaced in c. 1904 with a catadioptric first order Fresnel lens made by Chance Brothers. This rotated on bath of mercury, set on a cast-iron 'pedestal' (1.75m in height). The lens and pedestal are recorded in detail in a drawing (No. 8420) dated September 1903. A new floor was installed within the lantern, shown in a drawing (No. 8457) dated December 1903. The date of the plan for the new floor, probably indicates that all of the work took place in 1904, assuming that the new floor had to be installed prior to the pedestal and lens. A further drawing (No. 10304) is dated March 1924 and largely repeats the details of the 1903 drawing for the lens and pedestal. But the roof shows considerable alteration from the ball-finial and weathervane shown in 1903, to a cupula and weathervane. This alteration is noted on Douglas Hague's (1994: 50) section drawing of the lighthouse and may be assumed to have taken place in c.1924.

Event and Historical Information:

A lighthouse was first established on The Skerries circa 1716/17, built by William Trench as a personal venture, and with a patent established in 1714. His son-in-law Sutton Morgan took over the light in 1725 (confirmed by parliament in 1730 when he was granted the patent of the light to him and his heirs for ever). In c.1759 the lighthouse was rebuilt for around £3000 as a slightly tapering limestone tower 6.65m (21ft 10in) in diameter and about 8.5m (28ft) high. It was lit by a coal brazier. In 1778, it was inherited by Morgan Jones, High Sherriff of Cardiganshire, who in 1804 raised the height by a further 6.7m (22ft) and added an oil-burning lamp, enclosed by an iron balcony and lantern glazed with square panes. Trinity House acquired the lighthouse in 1844 for the record sum of £440,984, and under its auspices, it was largely rebuilt in 1851 by James Walker, consultant engineer.

The modern light shines at a height of 36m (119ft) above the mean high-water, and shows a double flash every 15 seconds, with a range of 20 nautical miles. It was automated in 1987 and is controlled from Trinity House's Planning Centre at Harwich in Essex.

Sources include:

Cadw Listed Building 18028: https://cadwpublic-api.azurewebsites.net/reports/listedbuilding/FullReport?lang=&id=18028

Eames, A, 1973, Ships and Seamen of Anglesey, pg 321.

Dodd, A H, 1971, The Industrial Revolution in North Wales, pg 123.

Davies,H R, 1924 and 1928, `An Account of the Private Lighthouse of the Skerries', Transactions of the Anglesey Antiquarian Society

Hague, D, 1994, Lighthouses of Wales: Their Architecture and Archaeology, pg49-52

Report of the Select Committee on Lighthouses, Parliamentary Papers, 1845.

Trinity House Archive. Drawing No. 1785, 1843. Skerries Lighthouse, New Lantern

Trinity House Archive. Drawing No. 8420,  September 1903. Skerries Lighthouse.

Trinity House Archive. Drawing No. 8457, December 1903. Skerries Lighthouse, New Lantern Floor.

J. Whitewright, RCAHMW, July 2024.