Hello, Alex, welcome!
Talk about the 4x4 offroad trails you have in Russia. Snow.. cliffs, rivers, erosion... Muddy terrains? Russia is a huuuuge country, I believe it is a paradise for somebody to get lost around there... Hehehe...
In my region in Brazil we have lots of dunes. I have never heard about dunes in Russia.
So, friend, keep in touch!