There is a place in Ukraine that is known as a birthplace of famous Polish king Jan III Sobieski. This is the Olesko Castle that is located not far from Ukrainian city Lviv.
It was built between 13th and 14th centuries as defensive fortification at the territorial border of Polish-Lithuanian Principality. In those days Olesko Castle was an outpost against the Tatar-Mongols and Turks. They say, many times invaders tried to conquer it but the castle resisted and was restored every time. » Read more..