Caldey Lighthouse is located on a small island around two and a half miles offshore from Tenby. Access to the island is strictly controlled, as the island is privately owned. Boat trips regularly depart for the island from Tenby.
The first record of a monastery dates back to over 1,500 years. The current Abbey was built in 1910 by Anglican Benedictine monks but sold to Belgian Cistercian monks in 1929.
Traders of Carmarthen made an application to build a lighthouse on Caldey Island in March 1827. Coastal traffic needed the light to assist the transportation of limestone and coal to central and North Wales. Transatlantic trading vessels also needed confirmation that they were at the Bristol Channel entrance rather than the English Channel.
Caldey Lighthouse was built on the highest point of the island at Chapel Point above the southern cliffs. The lighthouse worked in conjunction with Lundy Lighthouse 32 miles to the south. At Lundy, the light was often obscured by fog at an elevation of 538ft. The tower at Caldey had an elevation of 206ft, so was generally less obscured by fog.
The light at Caldey was first exhibited on 26th January 1829 showing a fixed white light, produced by 20 Argand oil lamps mounted in polished reflectors.
The lighthouse was improved in 1868, and undertaken by James Douglass. The service room and lantern floors were strengthened to receive a new second-order optic. The original lantern was replaced by a helically framed design with diagonal glazing.
The new light continued to show a fixed light white from the northeast round to the west, with red sectors showing to the north towards Tenby and the Woolhouse Shoal, and west towards Old Castle head near Lydstep. To the northwest, the light displayed a white sector.
Originally a dwelling attached to the lighthouse housed the keeper and his family. However, following improvements to the lighthouse, it became operated by two lighthouse keepers and their families. The lighthouse keepers’ dwellings were substantially extended. On either end of the original cottage, a separate lean-to was built for use as a pantry and scullery. The two new cottages were linked to the tower by a covered passageway.
In 1885 a clockwork mechanism was installed, and the light was subsequently converted to an occulting character. The character was altered again in 1889.
Prior to the First World War research was underway regarding the use of Acetylene gas. However, this was delayed during the War. Following improvements with the gas stability, some lights were converted to automatic operation in the 1920s, especially where no electricity was available.
Caldey Island Lighthouse was installed with Acetylene, using a Dalen sun valve. The keepers and families left the island, and an islander was employed as an Attendant.
The cottages were transferred to the island’s management and provided accommodation for the island workers.
During the mid-1900s, the character was altered to group flashing 3 every 20 seconds.
In November 1997, Caldey Lighthouse became the last to be converted from Acetylene gas and was connected to the island’s mains power supply with battery backup. The Acetylene burner and sun valve are at the base of the tower.