Saint Isaac's Cathedral - Wikipedia
Saint Isaac's Cathedral or Isaakievskiy Sobor (Russian: Исаа́киевский Собо́р) in Saint Petersburg, Russia, is the largest Russian Orthodox cathedral (sobor) in the city. It is the largest orthodox basilica and the fourth largest (by the volume under the cupola) cathedral in the world. It is dedicated to Saint Isaac of Dalmatia, a patron saint of Peter the Great, who had been born on the feast day of that saint.
via : en.wikipedia.org
The church on St Isaac's Square was ordered by Tsar Alexander I, to replace an earlier structure by Vincenzo Brenna, and was the fourth consecutive church standing at this place. A specially appointed commission examined several designs, including that of the French-born architect Auguste de Montferrand (1786–1858), who had studied in the atelier of Napoleon's designer, Charles Percier.
The interior was originally decorated with scores of paintings by the great Russian masters of the day. When these paintings began to deteriorate due to the cold, damp conditions inside the cathedral, Montferrand ordered them to be painstakingly reproduced as mosaics.
Reproducties van kerken gebouwd voor Tsar Alexander I, die trouwens op deze foto de werken discreet superviseert.