Opened in 1895 on the orders of Tzar Nicholas II, this was the first art museum in the country.  Its 400,000 pieces of art range from Russian icons of the 13th century through to the 20th century: be prepared to spend lots of time here if you're interested in art and Russian history. The masterpieces at the museum include Kazimir Malevich's Black Square, the epic Last Day of Pompeii by Karl Briullov, Ivan Aivazovsky's magnificent seascape The Ninth Wave, Ilya Repin's Barge Haulers on the Volga, and Valentin Serov's nude portrait of Ida Rubinstein. Note that tickets are cash only.