아무것도 보이지 않았다
Use 아무것도 before a negative verb to mean "nothing" or "not anything." This pattern is very useful when you want to say that there was no visible, audible, or noticeable thing at all. It is a productive way to describe complete absence.
어두워서 아무것도 보이지 않았다.
It was dark, so nothing could be seen.
