“Every surface in the chapel had been carved with symbols— Christian cruciforms, Jewish stars, Masonic seals, Templar crosses, cornucopias, pyramids, astrological signs, plants, vegetables, pentacles, and roses. The Knights Templar had been master stonemasons, erecting Templar churches all over Europe, but Rosslyn was considered their most sublime labor of love and veneration. The master masons had left no stone uncarved. Rosslyn Chapel was a shrine to all faiths … to all traditions … and, above all, to nature and the goddess.”
― Dan Brown, The DaVinci Code

Wrack, ruin, and restoration is a nutshell history of Rosslyn since its construction began in 1446. And mysterious speculations of course abound.