There’s this really good three part book series that an American who moved to Estonia has written, gives you a good outlook of what Estonians and living in Estonia is like from his perspective, very funny too(but maybe that just because I read it and am Estonian) Amazon link here
I’m not sure if it might be a little much for an 11-year-old, but there’s always this - history of trains around the world across the last 200 or so years. Lots of photos, some amazing information. On the link you can see some sample pages, might be worth looking and seeing if you think it’ll be alright for your nephew? Rails Around the World: Two Centuries of Trains and Locomotives
An interesting read on the vastness of Russia and, among others, the incredible low living standard in NK is The Border by Erika Fatland.
There was this 2013 book The Hole: Another Look at the Sinking of the Estonia Ferry on Sept. 28, 1994.
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>In September 1994, the passenger ferry Estonia set out on an overnight cruise from Tallinn, Estonia to Stockholm, Sweden and sank in the Baltic Sea, killing nearly 1000 people in 35 minutes. It was the worst peacetime sea catastrophe in European waters in the 20th century. A controversial government investigation blamed the ship's design and high waves. But the Estonia was the only intact ship in maritime history to sink in less than one hour -- faster than some torpedoed ships. This disturbing fact is the core of the tragedy and was left unexplained. The victims still remain in the shipwreck in shallow depth just off the coast of Finland, a spot militarily guarded by Sweden. "The Hole: Another look at the sinking of the Estonia ferry on September 28, 1994" examines alternative explanations in view of post-Soviet chaos, proceeding from the theory that the Estonia had a hole -- from a collision or an explosion.
I'd recommend reading this book, it's written by an American who has lived here for many years. It's full of funny details about the peculiarities of life in Estonia. I think he still around, so can't be all that bad. ;)