Jeffrey Epstein signed a Will 2 days before his death leaving assets to a private trust called the 1953 Trust. There is speculation that this in an attempt to keep his heirs secret. 

A Will is a private document whilst an individual is a live, but a Will in probate becomes a public document open to public inspection. However, in this situation the trust would remain private. 

It is important to take legal advice when preparing a Will. To ensure that everything included in your Will you would want to be open to public inspection, and that you are protecting your personal legacy.