Preferably an alternative that is Free Liberating Open-Source Software/ FLOSS. I would have used Truecrypt, but it has been discontinued.
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions seeking product recommendations are off-topic as they become obsolete quickly. Instead, describe your situation and the specific problem you're trying to solve." – Mark, M'vy, Community, user10008, RoraΖ
TrueCrypt 7.1a has been forked into other projects, such as VeraCrypt, which just like TrueCrypt offers hidden volumes.
I can't comment on whether to trust TrueCrypt/VeraCrypt or not (since TrueCrypt's sudden discontinuation), but both are open-source so you can figure it out yourself, and there has been an audit on TrueCrypt recently (as of writing).