First of all, please remember that there were actually two Russian Revolutions, both in 1917. The first was the Februrary Revolution. In this rebellion, the Tsar was overthrown and a provisional government installed. The second was the October Revolution or the Bolshevik Revolution. In this, the provisional government was overthrown and the Bolsheviks (one faction of the communists) took power.
These revolutions took place to some extent in many urban centers of the country. However, the most important and best-known actions of the revolutions took place in the capital, which was at that time called Petrograd. This is the city that is now called St. Petersburg.
After the revolution came the Russian Civil War which was fought all over the country.