The city is hosting a Russian warship until Friday. According to SFGate.com, this is the first Russian surface warship to visit San Francisco in 147 years.
People can tour the Varyag, docked along the Embarcadero, from 10 a.m. to 1 p.m. Thursday. The ship sails back to Russia on Friday.
The ship visit is tied to Russian President Dmitry Medvedev's visit to San Francisco and Silicon Valley businesses this week.
You can read about the ship's history — in both wartime and peacetime — on SFGate.