One part of the castle complex, which was built on a hilltop, is known as the Upper Castle.
The complex is part of the National Museum of Lithuania, one of the largest museums in the country.
The Castle Complex has been inhabited since Neolithic times.
Prior to the 13th century, its structures were built from wood.
In the 13–14th centuries defensive walls, towers and gateways were built from stone; these were reorganized and expanded several times.
The only freestanding structures that remain intact are those at the Lower Castle.
The Royal Palace in the Lower Castle evolved over the years and prospered during the 16th and mid-17th centuries.
For four centuries the Palace was the political, administrative and cultural center of the Grand Duchy of Lithuania.
Many noblemen from Western Europe participated in this military campaign, including Henry, Duke of Hereford, the future king Henry IV of England, with 300 knights, and the Livonian Knights, commanded by their Grand Master.In the 13th and 14th centuries there were stone structures within the palace site; some archeologists believe that a wooden palace stood there as well.The stone Royal Palace was built in the 15th century, apparently after the major fire in 1419.He had the opportunity to study the architecture of the castles of the Teutonic Order and adopt some of their elements in his residence in Vilnius.The Upper Castle was reconstructed in Gothic style with glazed green tiling on its roof. Archaeological data shows that the site has been occupied since Neolithic times. The hill on which it is built is known as Gediminas Hill, about 40 meters (44 yards) in height and around 160 meters (170 yards) in length.During the rule of Gediminas Vilnius was designated the capital city; in 1323, the castle was improved and expanded.The Orders were seeking to conquer Lithuania, stating that their motivation was the conversion of pagan Lithuanians to Catholicism.Until the early 17th century, a prison for noblemen was located in the Upper Castle.It was used as a fortress for the last time during the invasion of the Russians in 1655, when for the first time in Lithuanian history, a foreign army captured the entire complex.