BACK in the autumn of 1941, when it appeared Moscow might fall to invading Nazi forces, the Soviet Union's leaders decided to make this city the nation's provisional capital.
Dictator Joseph Stalin remained in besieged Moscow to direct its defense, but many top Communist Party members, Soviet government officials, and foreign diplomats hastily moved to Samara to continue the war effort from the relative safety of the vast Russian interior.
Soviet forces were able to repulse the Nazi thrust during the final months of 1941. But Samara served as the seat of government, as well as home of the party's Central Committee, for almost two years, until it was clear the German Army was in permanent retreat.
Aside from several plaques on downtown buildings, there are few traces commemorating Samara's status as the wartime capital. And perhaps the most striking relic from that era is about 40 yards underground and was kept secret for almost 50 years: Stalin's bunker.
The bunker, designed to be Stalin's command post, was never used by the dictator, as he stayed in Moscow throughout the war. Burrowing 12 floors underground, it was built under the temporary Communist Party headquarters, an inconspicuous building on Samara's Chapayev Square.
Construction was carried out in complete secrecy, taking 600 workers nine months to complete in the fall of 1942. In all, the bunker builders, who had helped construct the Moscow metro in the late 1930s, removed more than 25,000 cubic yards of earth without anyone finding out about it.
``There were foreign embassies nearby - Canadians and Swedes - but no one ever noticed that construction was going on,'' says Timofei Zakharchenko, the curator of the Stalin Bunker Museum. ``It's still a mystery as to how they moved all that earth.''
The bunker's existence remained a tightly held state secret until it was declassified in 1990 and turned into a museum.
The bunker's top floors now contain exhibits on the history of Soviet civil defense, and on Samara as the wartime capital.
The bottom floor, where Stalin's unused living quarters and cavernous war-room are located, is being preserved as it was during the war. The bunker's power and air systems have been maintained and are in perfect working order.
In some ways the bunker reflects Stalin's suspicious and paranoid nature.
Its depth, for example, far exceeded that of the bunkers of other World War II leaders. Nazi dictator Adolf Hitler's famed bunker was only 16 yards underground, while British leader Winston Churchill's shelter was only about 10 yards beneath London, Zakharchenko said.