The Admiralty building is the former headquarters of the Admiralty Board and the Imperial Russian Navy and since 2012 once again the headquarters of the Russian Navy.The building was re-built in the 19th century to support the Tsar's maritime ambitions. The original design was a fortified shipyard which was later surrounded by five bastions and further protected by a moat.
The Empire Style edifice visible today lining the Admiralty Quay was constructed to Andreyan Zakharov's design between 1806 and 1823. Located at the western end of the Nevsky Prospekt, The Admiralty with its gilded spire topped by a golden weather-vane in the shape of a small sail warship (Korablik), is one of the city's most conspicuous landmarks and the focal point of old St. Petersburg's three main streets - Nevsky Prospect, Gorokhovaya Street, and Voznesensky Prospect - underscoring the importance Peter I placed on Russia's Navy.
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.