We left Siberia by taking the Trans Siberian railroad from Novosibirsk to Nahodka and thence to Nahodka where we took a Russian ship to Yokohama (Tokyo), Japan.
We were paid some spending money in rubles and had a very hard time spending it all. We were able to buy some souvenirs with rubles (hand painted trays, fur hats) but there just was very little to buy. Hence we booked our Trans-Siberian tickets and purchased passage on a Russian ship to sail to Japan in order to use up more rubles.
The original plans for a Trans-Siberian railway to connect St. Petersburg, the then capital, to Vladivostock, were approved by Czar Alexander II and the line was built between 1891 and 1916. The main route of the Trans-Siberian originates in St. Petersburg and runs through Moscow, Chelyabinsk, Omsk, Novosibirsk, Irkutsk, Chita, Blagoveshchensk and Khabarovsk to Vladivostok for a length of 9289 km. We didn't travel the whole thing since we got on in Novosibirsk (km 3335). The train operates on Moscow time, so as long as you're on the train, you don't have to worry about time zones.
We got special food for May Day plus we were warned the food was not very good on the train, so we went prepared with a supply of fresh, salted, smoked, and tinned food and champagne and other liquor. The food wasn't that bad on the train either. At stations, people would buy food, like hot potatoes. There was a lot of trading of goods going on at stations.
It was not allowed to take pictures from the train or even of the train in stations. The train windows were also dirty even when we did sneak some pictures.
We arrived very early in the morning in Khabarovsk and would have liked to get some sleep, but Intourist wanted $100 (yes, that's dollars and it was 1979) for a few hours sleep in a hotel, so we just explored the town until evening when our train left.
Between 1950 and 1991, foreigners were not allowed in Vladivostock and the train that runs along the Amur river operated at night (so we foreigners couldn't see anything) and took us to Nahodka where we could get ships. It was such a beautiful train, I felt like staying awake all night just to look at it, all brass and dark woods, with a shared bath between every two cabins in our car. But it got cold and we got sleepy, so we went to sleep.