Photo of Nestorian Stele, Xi'an, as seen ca. 1892, near the (former) Buddhist temple Chongren in Xi'an. As Keevak (2008) explains (p. 6), the thing seen at the bottom is the head of a <i>bixi</i> tortoise onto which the stele was, presumably, installed after being unearthed in the 17th century.
Stele text by Nestorian monk <a href="https://en.wikipedia.org/wiki/Jingjing_(Christian_monk)" class="extiw" title="en:Jingjing (Christian monk)">Jingjing</a>. Photo either made by Henri Havret, or a local collaborator of his, or reproduced from an earlier Chinese source. There is a caption in Havret's 1895 publication, possibly explaining the provenance, but it's hardly legible.
The photo was originally published by Henri Havret (1848-1901), in his <a rel="nofollow" class="external text" href="https://archive.org/details/lastlechrtienne01havrgoog"><i>La stele chrétienne de Si-ngan fou</i> (part 1)</a>, <i>Variétés sinologiques</i> No. 7, Paris, 1895, near the front cover. This scan is as reproduced as Plate III in SIR E. A. WALLIS BUDGE, KT.,  <a rel="nofollow" class="external text" href="http://www.aina.org/books/mokk/mokk.htm">THE MONKS OF KUBLAl KHAN EMPEROR OF CHINA</a> (1928)