If you are interested in abandonned buildings, places, and things then the train graveyard is a must see! I had seen a post that it was somewhere in Krakow area but found it hard to find more information. After cycling there from Krakow center, which is a nice ride, I found that the site of the train graveyard is actually on the main train line with a station right next to it!
There is a long pedestrian bridge with steps leading down to the trains, the trains are unfenced and can be explored.
Very atmospheric and great for photos and thinking about the busy lives that the trains have had, now to be resting up here.
Be wary as there are some undesirables hanging out there too, so perhaps dont take all your expensive kit and dont be too naive going to a place like this.