[sandworm101]

Dude. Veracrypt. Hidden volumes. This is an old and well-solved problem set.

[NetMageSCW]

Hidden volumes aren’t that hidden if Veracrypt can find them.

[loneboat]

iirc it's even invisible to veracrypt until it has your correct password in hand. The hidden volume headers are indistinguishable from random bytes (which Veracrypt fills the volume with on creation).

[marysol5]

They are hidden if one of the "sources" to find them is only known to the user.