On reading up, "finding" isn't quite accurate, as the locations of these two shuttles were perfectly well known. They're OK-1K2 and OK-4M on Wikipedia's list below, located in MZK building 80, area 112a, Baikonur Cosmodrome, Kazakhstan:
https://en.wikipedia.org/wiki/Buran_programme#Buran-class_sp...
However, obviously sneaking in to take pictures is not an everyday occurrence, it's still a Russian military base and parts of the site remain in active use for the Russian space program.