The museum is dedicated to the Swedish naval defense and the preservation of history. It was founded by decree of Karl 11 in Karlskrona (Karl's crown) in 1752, when the city was the main base of the Swedish Navy, it carefully preserves models of Swedish ships and shipbuilding equipment, the building has naturally been modern for a long time. Now it's closer to our days....With all due respect to the history of the Royal Swedish Navy!!! In the 80s, the Swedish Navy's sonar picked up suspicious signals, which it identified as the noise of Soviet submarines. Search teams have been trying for months to find ways to invade, but to no avail... After the collapse of the USSR, the mysterious signals continued. Therefore, the Swedish leadership has created a research group to study what is happening. In 1996, Professor Magnus Wahlberg conducted research and found out that this was the sound that a herring makes when its swim bladder contracts and excess gases come out in the form of air bubbles. This release structure is unique and is found only in herring. Conclusion: when it seems to you that you are doing meaningless work, remember: Swedish navy sailors have been listening to herring being released from gases for 15 years.........