A number of traditions inherited from Celtic times are observed by the Cistercian monks of Caldey Abbey, the owners of the island.

The monks' predecessors migrated there from Belgium in the early 20th century, taking over from Anglican Benedictines who had bought the island in 1906 and built the extant monastery and abbey but later got into financial difficulties.

In the spring and summer, visitors are ferried to Caldey, not only to visit the sacred sanctuary but also to view the island's rich wildlife.

Kald ey translates as "cold island", with the name appearing as 'Caldea' in the early 12th century, and Kaldey or Caldey by 1291.

[10] Potter's Cave was found in 1950 by a monk named James Van Nedervelde, and excavations, which continued until 1970, initially revealed stalagmites in which tools and animals were embedded.

All the finds were carbon dated and have been preserved in the Abbey of Caldey Island or in Tenby Museum and Art Gallery.

[13][14] Following the Norman Conquest, Robert fitz Martin, Lord of Cemais, gave the island to his mother Geva.

[15] In the 12th century, Caldey Priory (now a Grade I listed building[16]) was established by Tironensian monks as a daughter house of St. Dogmaels Abbey, and lasted to the Dissolution of the Monasteries in 1536.

[19] The current abbey was built in 1910 by Anglican Benedictine monks but financial problems beginning in 1925 led to the 1929 purchase of the property by Belgian Cistercians.

The roofs are of white roughcast with red tiling, and the abbey church has five side-windows and on the south a "tapering" tower with primitive crenellations.

[24] Father Thaddeus Kotik was found to have sexually abused six girls on the island between 1972 and 1987 in a 2017 civil court case.

[28] In 2017 Welsh Conservatives children's spokesman, Darren Millar, called for an independent inquiry into historical child sexual abuse on the island.

Monks have agreed to a 'no touch' policy for visitors and will report any accidental physical contact, as recommended by the independent review.

The island lies in Carmarthen Bay on the northern side of the Bristol Channel in the county of Pembrokeshire, a little over 2.5 miles (4 km) south of Tenby on the mainland of southwest Wales.

A fleet of traditional wooden boats ferry passengers from Tenby to Caldey Island in the spring and summer months when the weather allows.

[citation needed] The average high and low temperatures for Caldey Island, along with wind speeds for each month of the year, are given in the following table.

The island also has some basic farming equipment including two tractors, used for the upkeep of the land and transportation of heavy goods.