Event Factoid: Paul went to
a certain large cave in the side of a certain high rock on the banks of
the Tigris at
a place called Surtha, and he erected a cross and traced the plan for
a small oratory.
Sources:
E. W Brooks, trans.,Lives of the Eastern Saints I,Patrologia Orientalis 17.1 (1923), https://archive.org/stream/patrologiaorient17pariuoft#page/n7/mode/2up, p: 111.