The Trinity Cathedral is located in the Pskov Krom or Kremlin on the east bank of the Velikaya River. It has, since 1589, been the mother church of the Pskov Eparchy.
The first wooden Trinity Cathedral was built in the tenth century, allegedly under the patronage of Princess Olga, but this seems unlikely as Olga's conversion was personal, and the conversion of the Rus Land did not occur until 988, almost two decades after her death. Thus, it seems likely the first church dates to the time of Christianization or shortly thereafter. This church was replaced by a stone church in 1138, allegedly at the behest of Prince Vsevolod Mstislavich, who died the previous year.
Wikipedia https://en.wikipedia.org/wiki/Trinity_Cathedral,_Pskov
Coordinates 57°49'19.6" N 28°19'44.27" E