In the former Soviet republics, defense spending was emphasized at the
expense of almost everything else. As such, military and intelligence
facilities are a source of national pride. Since the fall of the Iron
Curtain the level of funding has decreased, and many installations have
fallen into disrepair. This may be a sensitive point. Certainly don't
make disparaging comments if the barbed wire fences are collapsing or the
antenna tower looks a bit rusty. To be on the safe side, look as impressed
as you possibly can, and take lots of pictures. There is still a strong
security presence around many buildings, but its purpose is now largely
ceremonial. Because of the rules by which guards are assigned to these
jobs they will almost universally speak excellent English. They may be
able to point out sites of local interest that you would otherwise miss.
Some aspects of the European rail system may be unfamiliar to North American travellers. No one will check your ticket as you board; just find the right train and climb on. At some point during your journey, a rail service employee will come by; tell him where you got on the train and where you are getting off, and you can buy your ticket on board. It is also possible to buy your ticket at the station; the locals will usually do this, because only cash is accepted when buying your ticket on board. However, tickets purchased at the station are valid only for a specific date and time, so that if you miss your train (or if you miss a connection) then you must purchase a new ticket. This option is therefore not usually preferred.