 In "The Da Vinci Code",

Rosslyn Chapel's entrance was more modest than Langdon expected.The small wooden door had two iron hinges and a simple oak sign, Roslin.This ancient spelling, Langdon explained to Sophie, derived from the Rose Line meridian on which the chapel sat; or, as Grail academics preferred to believe, from the 'Line of the Rose' — the ancestral lineage of Mary Magdalene...

Mark Oxbrow and Ian Robertson state in "Rosslyn and the Grail"