One of the most important castles of the Grand Duchy of Lithuania once stood on Merkinė Hillfort. It was built on a high and steep hill (about 30-meter-high from the southern and eastern sides) sometime around the second half of the 13th century or the 14th century. In the beginning of the 15th century, the castle became the most important military and strategic center in the battles with the Teutonic Order.
