You're on a trip to Tykocin, drop by Kiermusy.
Great place, the building of the museum itself is very interesting.
There's a lot to see inside, including:
The weapon is related to the novel "Krzyżacy" by Henryk Sienkiewicz.
Medieval torture machines, gallows, guillotine.
Beautifully decorated rooms (in the style of residential rooms of the nobility).
The castle courtyard with battlements, towers, cannons and a dungeon.