Niżnie Rysy, The highest peak of Poland is a hike you can actually do from the Slovakian High Tatras and is a climb I would highly recommend when in the High Tatra region.
For reference, we hiked Rysy from the Slovakian side.
This hike takes a while to get interesting but when it does you will be rewarded with great views and the mental reward of knowing you have climbed to the highest peak in Poland and one of the highest in Slovakia.
The Green Lake (Zelene Pleso) in the High Tatras of Slovakia is a challenging summer hike that will test your endurance, but reward you with some stunning views of the Polish/ Slovakian mountain ranges!
This was one of two hikes I did in the High Tatras and just about takes the trophy home as my personal favourite.