I live in Moscow, Russia and use DIY indoor magnetic loop antennas to listen amateur radio. Recently I received quite strong signals from Italy (20m, IV3UTV) and Slovenia (40m, S51CK), both operators are ~2000 km from me. One thing I don't quite understand is that both countries are south-west from me, and the antenna is hanging on a window that faces east.
I see two possibilities. There is a tall concrete building not far away that probably could reflect those signals. Or maybe short waves can just pass through my building? What explanation is more plausible?
(I tried to find the answer on my question using Google. Everyone is telling on how short waves reflect off the ionosphere, but I didn't manage to find the information on how they behave when they meet a concrete building.)