During my travels I've started to focus on certain features of the destinations I'm visiting, especially signs and more recently doors. I find them to be quite interesting and often reflective of the folks that built and use them.
The doors we encountered in Poland were as about as expected. Strong, sturdy, solidly-built and often utilitarian, but with some having a unique and interesting artistic flare.
Here are some of the doors we saw in Krakow: