As many times as I have seen this signature icon in pictures, when I came around the corner and it came into my view, it still took my breathe away.

It is The Church of the Savior on Spilled Blood.  This Church was built on the site where Tsar Alexander II was assassinated and was dedicated in his memory.

On March 13, 1881, as Tsar Alexander‘s carriage passed along the embankment, a grenade thrown by an anarchist conspirator exploded. The tsar, shaken but unhurt, got out of the carriage and confronted the presumed culprit. A second conspirator took the chance to throw another bomb, killing himself and mortally wounding the tsar. The tsar, bleeding heavily, was taken back to the Winter Palace where he died a few hours later.