In the image, the "Neerja" actress is seen posing while lying on the upper berth of a train.
Sonam even made her husband Anand Ahuja nostalgic as he then shared his favourite train moment too.
"I also love trains...Let's go na, soon? The last time I went by rail was to Rishikesh but my most memorable one was to Bandhavgarh...Some 14-hour long trip with 40 classmates," Anand commented on Sonam's photograph.
The couple got married in May last year.
Sonam recently turned 34 and hosted a grand party for her family and friends from the film industry. On the work front, she is gearing up for the release of "The Zoya Factor".