What's the best way to lock a directory from remove & edits?

I have a few directories that I want to lock. This lock should provide the following: 1) Disallow anyone (including myself) from removing from that directory without a password 2) Disallow anyone (including myself) from changing existing files in that directory and recursive directories without a password 3) It shouldn't prevent new files from being added by myself but should prevent it from others (but not root) I am using Operating System: CentOS Linux 7 (Core). How can I achieve this behavior?