By Josh Kamins

Snaking through China’s western frontier, three of the country's largest deserts converge at the Magao grottos in Dun Huang— a series of caves washed over by red sand and time.

Inside the grottos, slack-jawed visitors gawk at the 100-foot tall Buddha among other Buddhist relics. Yet with all there is to see here, certain elements of Christian influence appear to be restricted from public view.

Elements out of Dan Brown’s The Da Vinci Code can be gleaned from the walls of Magao. The novel popularized the role of the Holy Grail legend and Magdalene’s role in the history of Christianity.

"Most of the caves are open only for research and not for public access," said Jessica Tu, a grotto tour guide.

Of the caves bearing substantial reference to Christianity, none were accessible on a recent wind-swept afternoon in early July.

Symbols of fertility, the feminine principle, and repetitions of the number 12, all which are commonly associated with the origins of Christianity, are depicted in the grottoes, but not available to the public. Some of the caves show evidence of Gnostic influence.

This one-sided playing-up of the Buddhist symbols has fueled the controversy that dogged Silk Road scholarship for at least a century.

Unseen caves display controversial images pertaining to the inspiration from Gnostics on the Silk Road. Apsaras - nude female goddess figures that exemplify the feminine principle - surround a fish, or Ichthys, a symbol of Christ. The duck is an icon of the Holy Spirit as seen in cave number 257.

The sunken panel in cave number 407 depicts three rabbits, a metaphor for fertility and the resurrection of Christ - their ears create a triangle representative of the male principle - converging into a triangle pointing to the heavens. A bloodline of grape vines runs throughout the sunken mural in cave 209, along with latent images of Satanic Crosses - the alchemic symbol for sulfur.

Other clues such as repetition of the number 12, the Fleur de Lis - a symbol of Mary Magdalene, chalices, babies emerging from lotus flowers, and even the Lotus flower itself is emblematic of Mary’s womb; these are all Christian symbols. The bloodline of grapevines in cave 209 culminates with more Ichtys flanking a central cross.

Uighurs, a modern Muslim ethnic minority in China, were Gnostics before they converted - an early branch of Christianity whose influence stretched from the near east along the Silk Road into China and into the west as far as the Albegencien sect in France. They were a major presence on the Silk Road.

The Gnostics believed that Earthly existence was a prison and their souls would be released to the metaphysical world with the onset of an apocalypse. Gnostics were also fervent practitioners of alchemy. Dun Huang was home to an apocalyptic form of Buddhism centering on the Buddha of the future, their cosmic pessimism stemming from anti-Buddhist warfare by the Huns, animist Tibetans and, later, the Islamic Arabs.

As a savior figure, the Maitreya Buddha, or future Buddha, played a role comparable to the Messiah in the Judeo-Christian tradition. The Gnostics were later suppressed in a crusade sanctioned by the Vatican.