Tsentralnaya Square

Ruslan Shamukov/TASS
When you get back above ground, head to Ploschad Kaizera Vilgelma (Kaizera Vilgelma Square) – also known as Zamkovaya Ploschad (Zamkovaya Square) – which is now called Tsentralnaya Ploschad (Tsentralnaya Square). Look for the huge white and blue House of the Soviets (Dom Sovetov). There is a plaque on the rear wall of the castle ruins, which was set in 1904. On it is written Kant's most famous quote, "Two things fill me with constantly increasing admiration and awe, the longer and more earnestly I reflect on them: the starry havens without and the moral law within." To find the ruined wall with the plaque just head to Tsentralnaya Ploschad via the Leninsky Prospekt (Leninsky Avenue) underpass.

There is an archaeological site of the west side of the castle in Tsentralnaya Ploschad. In the summer you can take a tour through some of the castle's catacombs. Legend has it that you can still find old treasures here. Some say that this is where the Amber Room that disappeared from the Catherine Palace during World War II is hidden. The Amber Room was indeed in the castle from 1942 to 1945, but since then no one has yet been able to trace it.

Since it was established in 1255 and until the beginning of World War II, the castle had been reconstructed a number of times, serving as a fortress, royal residence and a museum. A huge variety of architectural styles including gothic, baroque, rococo, classical and romantic have been reflected in the exterior and interior design of this magnificent building, which is 100 metres (328 feet) long and 67 metres (220 feet) wide. The castle's tower rose 84.5 metres (277 feet) above the city. One of the castle's ceremonial halls was named the Muscovite Hall, after the ambassadors of the Russian Tsar Vasily III met here with Duke Albrecht to discuss their joint military campaign against Poland. The Muscovite Hall was the biggest in Prussia at 1,500 square metres (16,146 square feet). It hosted the coronation of Prussian king and warrior Frederick I in 1701. Kaiser Wilhelm I chose the castle's church for his coronation. At the beginning of World War II, Königsberg Castle accommodated the city and East Prussia administration, the state archives, ceremonial halls and museums.

The castle was severely damaged by the British bombing in 1944 and urban warfare in April 1945. In 1967 the ruins were deconstructed entirely. Today there are plans to reconstruct the castle and restore the pre-war downtown as part of the "Heart of the City" project.