In the historical center of Kaliningrad is the exposition of the Museum under the open sky "Royal castle", created on the site of the excavations of the ruins of the ancient castle of the Teutonic order, founded in 1255. Castle of Koenigsberg, which gave the city its name, was the last refuge (1942-45 years) of the famous Amber room. The oldest landmark of the city was destroyed in 1967, and in the South-Eastern part of the castle was built the House of Soviets.

At the confluence of two branches of the river Pregel in 1255 had built a castle-fortress of the Czech king Ottokar II. Later, the wooden structure was replaced by buildings of brick and stone. The castle was rebuilt several times and changed in accordance with its purpose, combining the diversity of architectural styles. In the late nineteenth century fortification turned into a Museum complex and became the center of spiritual life. In the early twentieth century, the castle consisted of several buildings: the Castle Church (the place of coronation of the Prussian kings), "Silver library" with a collection of ancient books and manuscripts, a large "Hall of Muscovites" for receptions, an ancient octagonal tower Haberturk, castle tower (the tallest building, height 84, 5 meters), "Royal wing" with a throne, mirror, leather, hunting, ceramic halls and Royal chambers. Also on the grounds of the castle were the shelter "Firmare", a wine bar (in the basement of the castle) "Bloody justice" and "king of the pond" adjacent to the North-East. Before 1945 in königsberg castle was occupied by various public and management of institutions of East Prussia.

In 1944-1945, the castle was badly damaged by aerial bombardment and storming of Koenigsberg. From 1945 to 1967 historic building stood in ruins. In 1967, despite the protests of scientists and citizens, the main tower and walls of the medieval castle were blown up by the decision of the first Secretary of the regional Committee. On the site of the castle with 700 years of history is an area of "Central". Since 2001, the area was conducted archaeological excavations of the workers of the Baltic expedition and historical and art Museum. In 2008 due to lack of funding the excavations were discontinued, and in the ancient ruins was opened observation deck.

In the open air Museum presents the exhibition: "the history of the Royal castle", a story about the founding of königsberg and the rich history of the Royal castle, as well as interactive exposition "Forward to the past", where visitors can try on a suit of armor, riding horses, archery. During the tour visitors will learn the legends and beliefs of citizens of the past centuries, a unique archaeological findings (relevant to the Teutonic order) and the amazing part of historical-cultural landscape of a medieval castle. On-site observation platforms are located underground structures of the foundations of the Castle tower, West wing, part of the Foundation of the House convent, portal stones, and covering parts.

Observation deck "Royal castle" is an amazing place where visitors are surrounded by an atmosphere of secrets and mysteries, one of which is the Amber room, which disappeared from the castle during the war.