Rokantiškės Castle was located east of Vilnius on a high hill near the Vilnia River. First castle was built in 12th century. In 16th century, it was rebuilt in the Renaissance style and has been the seat of the Olshanski family. Alexander Olshanski, Yuri Olshanski and the last family member Pawel Olshanski have lived there. After his death the castle was inherited by Bona Sforza and later passed to the Pac family. The Deputy Chancellor of Lithuania Stefan Pac was visited here by the King of Poland and Grand duke of Lithuania Władysław IV Vasa on July 15, 1636.
The castle was burnt down by Cossacks on August 7, 1655 during the Russo-Polish War and fell in ruins. Today there are the only visible medieval castle ruins in Vilnius.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.