The lighthouse is intended to guide ships around a number of rocky shoals that cause a hazard to shipping entering the Haven as well as Crow's rock. The current lighthouse was completed in 1841 (at which time it was known as "St. Ann's Low Light") and commissioned by John Knott, senior lighthouse keeper with Trinity House. The first lighthouse on this site was built in 1714.
The present operational tower is 13 metres in height (42.7 feet) and is painted white. You can easily see Skokholm Lighthouse on the small island of Skokholm 5 miles to the west.