In Nicholas and Alexandra, Robert K. Massie wrote:
During the length of the ceremony, Alexandra later wrote to one of her sisters that she had never felt tired, so strong were her emotions. To her, the ceremony seemed a kind of mystic marriage between herself and Russia.
There are 2 books out about the Romanovs "happy times" during their reign
1 "A life for the Tsar" (Triumph & Tragedy at the Coronation of Emperor Nicholas II) by Greg King & Janet Ashton.
2 "The Tsar's Happy Occasion" Ritual & Dynasty in the Weddings of Russia's Rulers 1494-1745 by Russell E Martin.
That's the Triumphal Arch of Moscow which was erected between 1829–34 to commemorate Russia's victory over Napoleon.
The Arch was dismantled by order of Stalin in 1936 but restored in 2012 to mark the 200th anniversary of Russian victory of 1812.