This is the most famous castle in Ukraine. It is located on steep cliffs in the city of Kamianets-Podilskyi, Ukraine. It was built in the 11th century. This fortress has 11 towers and was once considered impregnable. Already in the 14th century, it gained fame as one of the most important fortifications in Eastern Europe. Today, it is one of the Seven Wonders of Ukraine and a UNESCO World Heritage Site.