Laugh if you like , there has long been rumors and speculation about a lake in Switzerland which connects to Loch Ness via a natural tunnel that was formed in the volcanic and ice age . It is claimed the Germans knew about this also . There is zero visibility at the bottom of Loch Ness , making it difficult to find the entrance , this legend goes way back to WW11 . Remember that this was all land mass before the ice age carved its way through , creating Islands such as the UK. It is feasible that folklore continued the story of a large tunnel and the Germans who sought Historical artifacts came across something that documented this .