▁of ▁Cal de y ▁Island , ▁three ▁miles ▁( 5   km ) ▁off ▁the ▁south ▁P embro kes hire , ▁Wales ▁coast line , ▁a ▁small ▁island ▁inhab ited ▁by ▁a ▁C ister cian ▁monaster y . ▁ ▁Const ruction ▁and ▁dimensions ▁An ▁application ▁to ▁build ▁the ▁L ighth ouse ▁was ▁made ▁in ▁March ▁ 1 8 2 7 ▁on ▁beh alf ▁of ▁trad ers ▁in ▁Car mar then ▁Bay . ▁It ▁was ▁commission ed ▁by ▁Tr inity ▁House ▁and ▁built ▁by ▁Joseph ▁Nelson ▁at ▁a ▁cost ▁of ▁£ 4 , 4 6 0 . ▁The ▁light ▁was ▁first ▁lit ▁in ▁ 1 8 2 9 . ▁ ▁The ▁L ighth ouse ▁is ▁a ▁squ at , ▁round , ▁brick - lined ▁lim estone ▁tower ▁of ▁ 1 7 . 0 7   m ▁( 5 6   ft ), ▁with ▁walls ▁ 0 . 9 1   m ▁( 3   ft ) ▁thick ▁at ▁the ▁base ▁and ▁ ▁thick ▁at ▁the ▁top . ▁The ▁light ▁stands ▁ 6 4   m ▁( 2 1 0   ft ) ▁above ▁high - water ▁mark . ▁It ▁acts ▁in ▁conj unction ▁with ▁the ▁Lund y ▁North ▁l ighth ouse ▁to ▁the ▁south , ▁and ▁has ▁a ▁range ▁of ▁. ▁The ▁former ▁oil ▁store ▁for ▁the ▁l ighth ouse ▁is ▁a ▁listed ▁structure . ▁ ▁Lan tern ▁and ▁lamp ▁ ▁The ▁present ▁lan tern ▁was ▁fitted ▁around ▁the ▁middle ▁of ▁the ▁nin ete enth ▁century ▁and ▁consisted ▁of ▁▁ 2 0 ▁Arg and