Wiki says about Trainspotting
Those who are "trainspotters" make an effort to "spot" all of a certain type of rolling stock. This might be a particular class of locomotive, a particular type of carriage or all the rolling stock of a particular company. To this end, they collect and exchange detailed information about the movements of locomotives and other equipment on the railway network, and become very knowledgeable about its operations. When a trainspotter sees a train that they have not yet seen before, it is referred to in the hobby as a "cop".
Maybe you can spot a nice train or start with a new hobby. But there is a cache to hunt, so focus :)
The cache is hidden under the bridge. There is no need to enter or come close to the rail tracks. Be careful! You will need special climbing gear to reach the cache. It's a secluded brdige without muggles, so take your time for proper safeguards. I recomment to go not alone, although it's possible to reach the cache single-handed. There are not many caches in Opole and surroundings which require climbing gear, so I hope this one is fun.
Update:
There is lot of construction going on due to the bypass road, which is build there. There will be a new bridge as well, but the construction hasn't started yet. Be careful.
The cache contains a log, a pen, some trinkets to trade and a travel bug. Have fun :)