Can my employer ask me to take a break?

I work in a hotel as an auditor, if I work alone on my shift BY LAW am I required to take a break? I work eight hours per night and am told I have to clock out for a 30 min break at least. Is this legal? I have no problems with taking one but I think someone should have to relieve me if I'm not getting paid. I do have a lot of downtime but that should have no effect on my wages.