It’s no secret that ‘Blue Planet II’ frequently offers up totally mind-blowing and “WTF?!” facts, but one in particular had viewers stunned on Sunday (5 November).

In the latest episode of Sir David Attenborough’s show, it was revealed that there are lakes at the bottom of the ocean. Yup. Actual lakes, in the sea:

For many viewers, this news was a lot to take in…
Lakes under the sea!? Fish with transparent heads!? And potentially the origin of life itself… A privilege to watch #Mindblown #BluePlanet
Noooooooooo to the eels diving into the salt lakes at the bottom of the sea #seasnakes #nope #blueplanet pic.twitter.com/bWPRAIyo4v
Blue planet literally blows my mind.. lakes in the sea?
There are lakes at the bottom of the ocean?! What the hell?! #BLUEPLANET
The current series of ‘Blue Planet’ sees Attenborough and his team make a number of new discoveries, filming aquatic life forms that, until now, had not been known to scientists.

Speaking to HuffPost UK, one of the production team members previously said that this is a pretty daunting task, admitting: “I’m always scared. I normally shut my eyes because I’m so scared!”