The Olesko Castle, oval in shape, stands on top of a small hill, about fifty meters in height.
A moat and a wall surround it, which made a good defence for the castle. The castle is also surrounded by a dense swamp.
The first historical records of the castle are in a document dated 1390.
In the 15th century, the castle was changed from being a defense point, to simply a getaway for aristocracy.
It's there where Polish King Jan III Sobieski was born and spent many years of his life.