Museum of the Battle of Grunwald is located in the pavilion under the amphitheater. There is also a small cinema room where you can see fragments of the film Krzyżacy (The Knights of the Cross), based on the novel by Henryk Sienkiewicz.
The exhibition opens with a bust of King Władysław Jagiełło. You can see here a large collection of medieval, spar and bladed weapons, as well as swords, vorpal swords, choppers, battle axes, then firearms and crossbows.