6 Baltic Sea Anomaly
Dubbed the Baltic Sea Anomaly, the object is a 70-metre long strangely-shaped feature that showed up on sonar laying 100 metres (300 feet) beneath the waves.
Theories as to what the Anomaly could be have ranged from the interesting to the outrageous, with some claiming it could be part of fleet of crashed UFOs on ocean floor.
Some conspiracy theorists even point out it bears a striking resemblance to the Star Wars Millennium Falcon with a steel grey appearance.
