Giacomo Antonio Domenico Quarenghi designed the Alexander Palace and the Hermitage Theatre. (The architect's name most heard in Saint Petersburg is Rastrelli, the architect of Catherine's Palace and the Winter Palace itself.)
My first career choice in middle school was architecture up until my drafting teacher told me that women do not get jobs as architects. That was 1959. I'm sure much has changed since then.
The Alexander Palace was the home of the last Czar and his family, Nicholas II and Alexandra. Unfortunately, time did not allow a trip to this Palace.
Photo: By Flying Russian (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
Quarenghi designed the Academy of Sciences Building below:
The Hermitage Theatre as seen from the palace Embankment - Photo by A. Savin - A picture of the Theater interior may be seen at the link I gave above. My pictures did not turn out due to the dim lighting.
Tolkien Bonus: Q is the Quenta Silmarillion, a history of the early days of Arda.