That's the newly-constructed Moscow State University glowing on the horizon.

Any of these girls alive today would now be in their 70s.

Jan wrote that the peninsula "had always been a resort area, and now when the happy workers get their holidays, the top ones get to come here."

Jan described Ukraine as "a cleaner, more individual part of the Soviet Union... this area has certainly seen and known more than just Soviet rule."

Jan said the train trips gave the Manhoffs their only chance to communicate with ordinary Russians "but here natural precaution prohibits anything but superficial talk."

As well as shooting images of city life, Martin, often accompanied by his wife Jan, travelled throughout Russia by rail. This image is one of several showing small town life far from Moscow.

When historian Douglas Smith discovered the images, he immediately realised he'd stumbled onto a rare treasure.

In Soviet days, many estates and palaces of the aristocracy were opened up as public parks.

Manhoff shot with 35mm Kodak and Agfa colour slide film. The technology was cutting edge in the US at the time, and would have been virtually unheard of inside the USSR.

Manhoff's job in Russia was as an assistant army attache at the embassy.

Under Soviet rule religion was heavily suppressed, and many churches were either destroyed or put to use as humble storage houses.

The pale spot on the coffin is a kind of clear plastic or glass bubble over his face.

Jan's first impressions of the city's shopping scene were scathing: "Nothing quite fits, the people as well as the furnishings. And nothing that is sold seems new, it all looks second-hand."

The only time the Manhoffs were permitted to leave the train during their journeys was during long stops at stations en route, though even then they were required to stay on the platform.

In the same letter Jan commented on the result of the 1917 "workers' revolution" which overthrew Russia's monarchy and capitalist system: "probably no picture of the 'revolution' is clearer, the workers have taken over and they do not yet quite how to handle it all, but there's noone else."

The country estate in Moscow was owned by the Sheremetev family before the Russian revolution.

As Martin photographed, Jan made notes on their experiences.

The New York Times reported on one of the Manhoffs’ trips deep into Siberia, claiming “Americans have never traveled to this remote area before.”

Two of the men sport freshly-shaved heads.

After a local man welcomed the unexpected foreigners by firing up an accordian, Jan writes "he played well and to everyone's pleasure. One Russian bought him a bottle of beer, and we donated a bottle. Then, it happened. The manager... walked in and told everyone that the cafe was closed. Everyone with a great deal of chatter wondered why and many "pochomoos" [Russian for 'why'] were voiced. Someone asked the accordian player why and he said 'I don't know, it's the first time in my life.' Then he very amusingly said 'well, I'll play you a march', and to the tune of Russian marches we vacated."

Despite brief encounters like this, the Manhoffs were unable to scratch beneath the surface of Soviet life at a time when mingling with foreigners could land Russians in real trouble. Jan wrote “we’ve never been inside a Russian home, nor can ever expect to be.”

The sign on left welcomes “Brothers from the Chinese Republic”.

Jan wrote that the police in Moscow were "so stationed as to never be out of sight of the next one." Under Stalin's rule the USSR was a police state in which millions of people accused of opposition to the totalitarian regime were either killed, or sent to labour camps in Siberia.

The final train adventure Martin Manhoff took ended the couple's time in the USSR. On a summer trip through Siberia in 1953 he and three colleagues were accused of illegally photographing airfields and oil dumps. The four were branded as spies and hastily evicted from the country.

The whole film is on youtube - look up: "Огни на реке."

The Hotel Ukraine skyscraper is under construction across the river.

Smith told Radio Free Europe/Radio Liberty "Manhoff captured this everyday quality... It gives a human quality that is missing from any other depiction [of life in the USSR in the 1950s.]"